I should please open an issue

gcm-diagnose.log

C:\Users\uie35418>git credential-manager diagnose
Running diagnostics...

[ OK ] Environment
[ OK ] File system
[ OK ] Networking
[ OK ] Git
[ OK ] Credential storage
[ OK ] Microsoft authentication (AAD/MSA)
[FAIL] GitHub API

[!] Encountered an exception [!]
System.Net.Http.HttpRequestException: Der Antwortstatuscode gibt keinen Erfolg an: 403 (rate limit exceeded).

   bei System.Net.Http.HttpResponseMessage.EnsureSuccessStatusCode()

   bei GitHub.GitHubRestApi.<GetMetaInfoAsync>d__5.MoveNext()

--- Ende der Stapelüberwachung vom vorhergehenden Ort, an dem die Ausnahme ausgelöst wurde ---

   bei System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)

   bei System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)

   bei System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()

   bei GitHub.Diagnostics.GitHubApiDiagnostic.<RunInternalAsync>d__2.MoveNext()

--- Ende der Stapelüberwachung vom vorhergehenden Ort, an dem die Ausnahme ausgelöst wurde ---

   bei System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)

   bei System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)

   bei System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()

   bei GitCredentialManager.Diagnostics.Diagnostic.<RunAsync>d__6.MoveNext()

[*] Diagnostic test log [*]
Using 'https://github.com/' as API target.

Querying '/meta' endpoint...

Diagnostic summary: 6 passed, 0 skipped, 1 failed.
Log files:
C:\Users\uie35418\gcm-diagnose.log

Caution: Log files may include sensitive information - redact before sharing.

Diagnostics indicate a possible problem with your installation.
Please open an issue at https://aka.ms/gcm/bug and include log files.

Reproduce the failure with git credential-manager diagnose and use the attached gcm-diagnose.log as the baseline. Start with the GitHub API diagnostic's /meta request and its handling of the 403 rate-limit response. The issue is complete when the cause and expected behavior for this failure are established and verified.