[ci-scan] Test failure: System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin [Content truncated due to length]

## Build Information
Build: https://dev.azure.com/dnceng-public/cbb18261-c48f-4abb-8651-8cdcb5474649/_build/results?buildId=1592310
Build error leg or test failing: windows-x86 Release NativeAOT_Libs-System.Net.Http.WinHttpHandler.Functional.Tests

KBE authoring guidance (ci-failure-scan)

- `Error Details` is for readers. Paste the full exception, stack trace, or build error excerpt so the failure is understandable without opening the raw log.
- Build Analysis parses only the single JSON block under `Error Message`.
- `ErrorMessage` is a case-sensitive ordinal `String.Contains` substring copied verbatim from the failing log.
- Set `BuildRetry` to `true` only for a clear infrastructure retry case. `ExcludeConsoleLog` disables Helix console-log scanning.

## Error Details

```
[FAIL] System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds(safeChar: '...', headerType: Cookie)
System.Net.Http.HttpRequestException : Error while copying content to a stream.
---- System.IO.IOException : The read operation failed, see inner exception.
-------- System.Net.Http.WinHttpException : Error 12030 calling WINHTTP_CALLBACK_STATUS_REQUEST_ERROR, 'The connection with the server was terminated abnormally'.
at System.Net.Http.HttpContent.WrapStreamCopyException(Exception) in /_/src/libraries/System.Net.Http/src/System/Net/Http/HttpContent.cs:line 708
at System.Net.Http.HttpContent.GetStreamCopyException(Exception) in /_/src/libraries/System.Net.Http/src/System/Net/Http/HttpContent.cs:line 699
at System.Net.Http.HttpContent.LoadIntoBufferAsyncCore(Task, HttpContent.LimitArrayPoolWriteStream) in /_/src/libraries/System.Net.Http/src/System/Net/Http/HttpContent.cs:line 524
```

Observed in the `NativeAOT_Libs` Windows legs of runtime-nativeaot-outerloop (def 265, build 1592310) and reproduced in the following build 1593527, so the failure is stable across builds. The `safeChar` / `headerType` theory arguments vary run to run, so the signature pairs the stable test-method name with the WinHttp `WINHTTP_CALLBACK_STATUS_REQUEST_ERROR` error.

## Error Message

```json
{
"ErrorMessage": [
"PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds",
"System.Net.Http.WinHttpException : Error 12030 calling WINHTTP_CALLBACK_STATUS_REQUEST_ERROR"
],
"ErrorPattern": "",
"BuildRetry": false,
"ExcludeConsoleLog": false
}
```

Agentic workflow metadata (ci-failure-scan)

Workflow artifact: ci-failure-scan
Artifact kind: kbe-verification
Verified match count: 1 hits in failure.log

---
Filed by [`ci-failure-scan`](https://github.com/dotnet/runtime/blob/main/.github/workflows/ci-failure-scan.md) (detection only). [`ci-failure-fix`](https://github.com/dotnet/runtime/blob/main/.github/workflows/ci-failure-fix.md) walks open `[ci-scan]` KBEs and either opens a small fix PR or comments here to loop in owners — it never disables the test.

> [!NOTE]
> This issue was generated by an AI agent (GitHub Copilot / ci-failure-scan workflow).

> Generated by [CI Outer-Loop Failure Scanner](https://github.com/dotnet/runtime/actions/runs/34694269201) · opus48 · 923.9 AIC · ⌖ 12.5 AIC · ⊞ 19.7K · [◷](https://github.com/search?q=repo%3Adotnet%2Fruntime+is%3Aissue+%22gh-aw-workflow-call-id%3A+dotnet%2Fruntime%2Fci-failure-scan%22&type=issues)

### Report

|Build|Repository|Test|Pull Request|
|---|---|---|---|
|[1597543](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1597543)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1597543&view=ms.vss-test-web.build-test-results-tab&runId=44104040&resultId=165565)|dotnet/runtime#133949|
|[1597340](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1597340)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1597340&view=ms.vss-test-web.build-test-results-tab&runId=44099112&resultId=120872)|dotnet/runtime#133940|
|[1597201](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1597201)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1597201&view=ms.vss-test-web.build-test-results-tab&runId=44098130&resultId=146028)||
|[1597167](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1597167)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1597167&view=ms.vss-test-web.build-test-results-tab&runId=44095198&resultId=181412)|dotnet/runtime#133935|
|[1597127](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1597127)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1597127&view=ms.vss-test-web.build-test-results-tab&runId=44093094&resultId=152496)|dotnet/runtime#133673|
|[1596986](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596986)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596986&view=ms.vss-test-web.build-test-results-tab&runId=44086116&resultId=177771)||
|[1596796](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596796)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596796&view=ms.vss-test-web.build-test-results-tab&runId=44084094&resultId=145770)||
|[1596674](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596674)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596674&view=ms.vss-test-web.build-test-results-tab&runId=44077378&resultId=150584)|dotnet/runtime#133763|
|[1596513](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596513)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596513&view=ms.vss-test-web.build-test-results-tab&runId=44076878&resultId=128366)||
|[1596323](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596323)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596323&view=ms.vss-test-web.build-test-results-tab&runId=44076826&resultId=136038)||
|[1596641](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596641)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596641&view=ms.vss-test-web.build-test-results-tab&runId=44076662&resultId=174545)|dotnet/runtime#133416|
|[1596321](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596321)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596321&view=ms.vss-test-web.build-test-results-tab&runId=44069020&resultId=151547)||
|[1596300](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596300)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596300&view=ms.vss-test-web.build-test-results-tab&runId=44069142&resultId=155528)|dotnet/runtime#133890|
|[1596241](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596241)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596241&view=ms.vss-test-web.build-test-results-tab&runId=44068078&resultId=139973)|dotnet/runtime#133884|
|[1595292](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595292)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595292&view=ms.vss-test-web.build-test-results-tab&runId=44050262&resultId=133308)||
|[1595348](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595348)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595348&view=ms.vss-test-web.build-test-results-tab&runId=44048730&resultId=170156)|dotnet/runtime#129683|
|[1595315](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595315)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595315&view=ms.vss-test-web.build-test-results-tab&runId=44047596&resultId=128086)|dotnet/runtime#133378|
|[1595259](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595259)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595259&view=ms.vss-test-web.build-test-results-tab&runId=44043308&resultId=132218)||
|[1595150](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595150)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595150&view=ms.vss-test-web.build-test-results-tab&runId=44042242&resultId=149785)|dotnet/runtime#133571|
|[1595201](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595201)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595201&view=ms.vss-test-web.build-test-results-tab&runId=44042000&resultId=141769)||
|[1594919](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594919)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594919&view=ms.vss-test-web.build-test-results-tab&runId=44031060&resultId=137235)||
|[1594893](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594893)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594893&view=ms.vss-test-web.build-test-results-tab&runId=44030416&resultId=132261)|dotnet/runtime#133384|
|[1594812](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594812)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594812&view=ms.vss-test-web.build-test-results-tab&runId=44028248&resultId=159691)|dotnet/runtime#132534|
|[1594801](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594801)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594801&view=ms.vss-test-web.build-test-results-tab&runId=44028208&resultId=123104)||
|[1594754](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594754)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594754&view=ms.vss-test-web.build-test-results-tab&runId=44026358&resultId=150731)|dotnet/runtime#133828|
|[1594695](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594695)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594695&view=ms.vss-test-web.build-test-results-tab&runId=44024546&resultId=168388)|dotnet/runtime#133827|
|[1594664](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594664)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594664&view=ms.vss-test-web.build-test-results-tab&runId=44023822&resultId=141107)||
|[1594658](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594658)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594658&view=ms.vss-test-web.build-test-results-tab&runId=44023264&resultId=137290)|dotnet/runtime#133819|
|[1594564](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594564)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594564&view=ms.vss-test-web.build-test-results-tab&runId=44019738&resultId=125617)||
|[1594550](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594550)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594550&view=ms.vss-test-web.build-test-results-tab&runId=44018462&resultId=172399)||
|[1594316](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594316)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandlerTest_Cookies_Http2.GetAsync_ReceiveSetCookieHeader_CookieAdded](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594316&view=ms.vss-test-web.build-test-results-tab&runId=44011784&resultId=153530)||
|[1594346](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594346)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594346&view=ms.vss-test-web.build-test-results-tab&runId=44011812&resultId=151031)|dotnet/runtime#133800|
|[1594333](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594333)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594333&view=ms.vss-test-web.build-test-results-tab&runId=44010994&resultId=147667)||
|[1594314](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594314)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594314&view=ms.vss-test-web.build-test-results-tab&runId=44010142&resultId=134796)||
|[1594067](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594067)|dotnet/runtime|[System.Net.Http.Functional.Tests.PlatformHandlerTest_Cookies_Http2.GetAsync_ReceiveSetCookieHeader_CookieAdded](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594067&view=ms.vss-test-web.build-test-results-tab&runId=44004114&resultId=151093)||
#### Summary
|24-Hour Hit Count|7-Day Hit Count|1-Month Count|
|---|---|---|
|14|35|35|

Start with the failing System.Net.Http.Functional.Tests.PlatformHandler_HttpClientHandler_Http2_Test.SendAsync_RequestWithLatin1HeaderValue_Succeeds entry point and the reported Windows NativeAOT build logs. Review the existing pull requests listed in the report before investigating further; done means the failing Windows legs pass without this error.

Written by the indexing model from the issue text.