RCNConfigRealtime trying to connect while in background

### Description

In `[RCNConfigRealtime retryHTTPConnection]` there's some early return:

```objective-c
// Retry mechanism for HTTP connections
- (void)retryHTTPConnection {
__weak RCNConfigRealtime *weakSelf = self;
dispatch_async(_realtimeLockQueue, ^{
__strong RCNConfigRealtime *strongSelf = weakSelf;
if (!strongSelf || strongSelf->_isInBackground) {
return;
}
```

This doesn't seem to work reliably. We have millions of non-fatals on Crashlytics that run into `FIRRemoteConfigUpdateErrorStreamError` and 99% of them report that the app is in background.

### Reproducing the issue

Unfortunately we don't have any steps on how to reproduce this, but in the screenshot above you can see that it happens very often on production.

### Firebase SDK Version

12.7.0

### Xcode Version

26.2

### Installation Method

Swift Package Manager

### Firebase Product(s)

Remote Config

### Targeted Platforms

iOS

### Relevant Log Output

```shell
Non-fatal: Error
Domain: com.google.remoteconfig.update.ErrorDomain Code: 8001 NSLocalizedDescription: Unable to connect to the server. Check your connection and try again.
```

### If using Swift Package Manager, the project's Package.resolved

Expand Package.resolved snippet

```json

{
"pins" : [
{
"identity" : "abseil-cpp-binary",
"kind" : "remoteSourceControl",
"location" : "https://github.com/google/abseil-cpp-binary.git",
"state" : {
"revision" : "bbe8b69694d7873315fd3a4ad41efe043e1c07c5",
"version" : "1.2024072200.0"
}
},
{
"identity" : "accessibilitysnapshot",
"kind" : "remoteSourceControl",
"location" : "https://github.com/cashapp/AccessibilitySnapshot.git",
"state" : {
"revision" : "8d4bc42c1ba23755147b931e1e94c775df91a997",
"version" : "0.10.0"
}
},
{
"identity" : "adjust_signature_sdk",
"kind" : "remoteSourceControl",
"location" : "https://github.com/adjust/adjust_signature_sdk.git",
"state" : {
"revision" : "b11c73304c2410bd410cc9369b812a83cc117002",
"version" : "3.61.0"
}
},
{
"identity" : "adyen-3ds2-ios",
"kind" : "remoteSourceControl",
"location" : "https://github.com/Adyen/adyen-3ds2-ios",
"state" : {
"revision" : "00862adbc079d0be943666a4ad2523deb31f9546",
"version" : "2.4.4"
}
},
{
"identity" : "adyen-authentication-ios",
"kind" : "remoteSourceControl",
"location" : "https://github.com/Adyen/adyen-authentication-ios",
"state" : {
"revision" : "04fe1a11b282721b5e55ef59c5417a3df41c5607",
"version" : "3.1.0"
}
},
{
"identity" : "adyen-ios",
"kind" : "remoteSourceControl",
"location" : "https://github.com/Adyen/adyen-ios",
"state" : {
"revision" : "3632faac5bbd30d55bf29ed8a01d4e15c85b2a7c",
"version" : "5.22.1"
}
},
{
"identity" : "adyen-networking-ios",
"kind" : "remoteSourceControl",
"location" : "https://github.com/Adyen/adyen-networking-ios",
"state" : {
"revision" : "43fd5d93f8587623eb134e3968f099e0417e74f6",
"version" : "3.0.1"
}
},
{
"identity" : "adyen-wechatpay-ios",
"kind" : "remoteSourceControl",
"location" : "https://github.com/Adyen/adyen-wechatpay-ios",
"state" : {
"revision" : "1127f793854d8624dbe6741d5c42be39dadd4f93",
"version" : "2.2.0"
}
},
{
"identity" : "alamofire",
"kind" : "remoteSourceControl",
"location" : "https://github.com/Alamofire/Alamofire.git",
"state" : {
"revision" : "7be73f6c2b5cd90e40798b06ebd5da8f9f79cf88",
"version" : "5.11.0"
}
},
{
"identity" : "algoliasearch-client-swift",
"kind" : "remoteSourceControl",
"location" : "https://github.com/algolia/algoliasearch-client-swift",
"state" : {
"revision" : "cc9a2f0c66c835d0eb851d03cf5001fb3a8fdaf5",
"version" : "9.37.2"
}
},
{
"identity" : "anyformatkit",
"kind" : "remoteSourceControl",
"location" : "https://github.com/luximetr/AnyFormatKit.git",
"state" : {
"revision" : "ae3a965164005b07f81d6aa066520d7ad14ea54e",
"version" : "2.5.2"
}
},
{
"identity" : "app-check",
"kind" : "remoteSourceControl",
"location" : "https://github.com/google/app-check.git",
"state" : {
"revision" : "61b85103a1aeed8218f17c794687781505fbbef5",
"version" : "11.2.0"
}
},
{
"identity" : "applovin-max-swift-package",
"kind" : "remoteSourceControl",
"location" : "https://github.com/AppLovin/AppLovin-MAX-Swift-Package.git",
"state" : {
"revision" : "b5acf713209298059bb2f09b22d84d523454bc7b",
"version" : "13.5.1"
}
},
{
"identity" : "auth0.swift",
"kind" : "remoteSourceControl",
"location" : "https://github.com/auth0/Auth0.swift",
"state" : {
"revision" : "03c85db911c2365208497907b82b91d0a774e4e7",
"version" : "2.0.0"
}
},
{
"identity" : "braze-swift-sdk",
"kind" : "remoteSourceControl",
"location" : "https://github.com/braze-inc/braze-swift-sdk",
"state" : {
"revision" : "8ed872cbd122f68333928597d2b2d2af52bdceb4",
"version" : "13.3.0"
}
},
{
"identity" : "cash-app-pay-ios-sdk",
"kind" : "remoteSourceControl",
"location" : "https://github.com/cashapp/cash-app-pay-ios-sdk",
"state" : {
"revision" : "25f526aec9b2535d0dc4485280bbf6c7d39e3424",
"version" : "0.6.2"
}
},
{
"identity" : "chalk",
"kind" : "remoteSourceControl",
"location" : "https://github.com/mxcl/Chalk.git",
"state" : {
"revision" : "a7f58e47a08ca5a84f73acc4bcf6c2c19d990609",
"version" : "0.5.0"
}
},
{
"identity" : "clarity-apps",
"kind" : "remoteSourceControl",
"location" : "https://github.com/microsoft/clarity-apps",
"state" : {
"revision" : "470c15abbb26a7500e992c68ef411f5e986d495d",
"version" : "3.4.2"
}
},
{
"identity" : "client-swift",
"kind" : "remoteSourceControl",
"location" : "https://github.com/Kameleoon/client-swift.git",
"state" : {
"revision" : "e938767a156dc562eae2b270a041be566135991a",
"version" : "4.22.2"
}
},
{
"identity" : "cwlcatchexception",
"kind" : "remoteSourceControl",
"location" : "https://github.com/mattgallagher/CwlCatchException.git",
"state" : {
"revision" : "07b2ba21d361c223e25e3c1e924288742923f08c",
"version" : "2.2.1"
}
},
{
"identity" : "cwlpreconditiontesting",
"kind" : "remoteSourceControl",
"location" : "https://github.com/mattgallagher/CwlPreconditionTesting.git",
"state" : {
"revision" : "0139c665ebb45e6a9fbdb68aabfd7c39f3fe0071",
"version" : "2.2.2"
}
},
{
"identity" : "filecheck",
"kind" : "remoteSourceControl",
"location" : "https://github.com/llvm-swift/FileCheck.git",
"state" : {
"revision" : "f7c5f1a9479b33a876a6f5632ca2b92a7ce4b667",
"version" : "0.2.6"
}
},
{
"identity" : "firebase-ios-sdk",
"kind" : "remoteSourceControl",
"location" : "https://github.com/firebase/firebase-ios-sdk.git",
"state" : {
"revision" : "45210bd1ea695779e6de016ab00fea8c0b7eb2ef",
"version" : "12.7.0"
}
},
{
"identity" : "google-ads-on-device-conversion-ios-sdk",
"kind" : "remoteSourceControl",
"location" : "https://github.com/googleads/google-ads-on-device-conversion-ios-sdk.git",
"state" : {
"revision" : "35b601a60fbbea2de3ea461f604deaaa4d8bbd0c",
"version" : "3.2.0"
}
},
{
"identity" : "googleappmeasurement",
"kind" : "remoteSourceControl",
"location" : "https://github.com/google/GoogleAppMeasurement.git",
"state" : {
"revision" : "c2d59acf17a8ba7ed80a763593c67c9c7c006ad1",
"version" : "12.5.0"
}
},
{
"identity" : "googledatatransport",
"kind" : "remoteSourceControl",
"location" : "https://github.com/google/GoogleDataTransport.git",
"state" : {
"revision" : "617af071af9aa1d6a091d59a202910ac482128f9",
"version" : "10.1.0"
}
},
{
"identity" : "googleutilities",
"kind" : "remoteSourceControl",
"location" : "https://github.com/google/GoogleUtilities.git",
"state" : {
"revision" : "60da361632d0de02786f709bdc0c4df340f7613e",
"version" : "8.1.0"
}
},
{
"identity" : "grpc-binary",
"kind" : "remoteSourceControl",
"location" : "https://github.com/google/grpc-binary.git",
"state" : {
"revision" : "75b31c842f664a0f46a2e590a570e370249fd8f6",
"version" : "1.69.1"
}
},
{
"identity" : "gtm-session-fetcher",
"kind" : "remoteSourceControl",
"location" : "https://github.com/google/gtm-session-fetcher.git",
"state" : {
"revision" : "a2ab612cb980066ee56d90d60d8462992c07f24b",
"version" : "3.5.0"
}
},
{
"identity" : "interop-ios-for-google-sdks",
"kind" : "remoteSourceControl",
"location" : "https://github.com/google/interop-ios-for-google-sdks.git",
"state" : {
"revision" : "040d087ac2267d2ddd4cca36c757d1c6a05fdbfe",
"version" : "101.0.0"
}
},
{
"identity" : "ios-snapshot-test-case",
"kind" : "remoteSourceControl",
"location" : "https://github.com/uber/ios-snapshot-test-case.git",
"state" : {
"revision" : "7b10770333a961be6e5a41c9ce04b8c6d3990126",
"version" : "8.0.0"
}
},
{
"identity" : "ios_sdk",
"kind" : "remoteSourceControl",
"location" : "https://github.com/adjust/ios_sdk",
"state" : {
"revision" : "fbe95360df63c3c0f9a98c5f2efb39b46bd2f08d",
"version" : "5.4.6"
}
},
{
"identity" : "jwtdecode.swift",
"kind" : "remoteSourceControl",
"location" : "https://github.com/auth0/JWTDecode.swift.git",
"state" : {
"revision" : "3cd207fb9e943b6168a117baa3936c823204c2dc",
"version" : "2.6.3"
}
},
{
"identity" : "leveldb",
"kind" : "remoteSourceControl",
"location" : "https://github.com/firebase/leveldb.git",
"state" : {
"revision" : "a0bc79961d7be727d258d33d5a6b2f1023270ba1",
"version" : "1.22.5"
}
},
{
"identity" : "lottie-spm",
"kind" : "remoteSourceControl",
"location" : "https://github.com/airbnb/lottie-spm.git",
"state" : {
"revision" : "69faaefa7721fba9e434a52c16adf4329c9084db",
"version" : "4.6.0"
}
},
{
"identity" : "nanopb",
"kind" : "remoteSourceControl",
"location" : "https://github.com/firebase/nanopb.git",
"state" : {
"revision" : "b7e1104502eca3a213b46303391ca4d3bc8ddec1",
"version" : "2.30910.0"
}
},
{
"identity" : "nimble",
"kind" : "remoteSourceControl",
"location" : "https://github.com/Quick/Nimble.git",
"state" : {
"revision" : "c93f16c25af5770f0d3e6af27c9634640946b068",
"version" : "9.2.1"
}
},
{
"identity" : "pathkit",
"kind" : "remoteSourceControl",
"location" : "https://github.com/kylef/PathKit.git",
"state" : {
"revision" : "3bfd2737b700b9a36565a8c94f4ad2b050a5e574",
"version" : "1.0.1"
}
},
{
"identity" : "prebid-mobile-ios",
"kind" : "remoteSourceControl",
"location" : "https://github.com/prebid/prebid-mobile-ios.git",
"state" : {
"revision" : "0b0dc9962eac145f1e8ee7c692c735cd274eaacd",
"version" : "3.2.0"
}
},
{
"identity" : "promises",
"kind" : "remoteSourceControl",
"location" : "https://github.com/google/promises.git",
"state" : {
"revision" : "540318ecedd63d883069ae7f1ed811a2df00b6ac",
"version" : "2.4.0"
}
},
{
"identity" : "quick",
"kind" : "remoteSourceControl",
"location" : "https://github.com/Quick/Quick.git",
"state" : {
"revision" : "8cce6acd38f965f5baa3167b939f86500314022b",
"version" : "3.1.2"
}
},
{
"identity" : "sbtuitesttunnel",
"kind" : "remoteSourceControl",
"location" : "https://github.com/Subito-it/SBTUITestTunnel",
"state" : {
"revision" : "24141a3e88175f027aeb86ea5df55d041a9cf63f",
"version" : "11.0.0"
}
},
{
"identity" : "sdwebimage",
"kind" : "remoteSourceControl",
"location" : "https://github.com/SDWebImage/SDWebImage.git",
"state" : {
"revision" : "36e79ba485e9bb4d3cd4e3318908866dac5e7b51",
"version" : "5.21.5"
}
},
{
"identity" : "simplekeychain",
"kind" : "remoteSourceControl",
"location" : "https://github.com/auth0/SimpleKeychain.git",
"state" : {
"revision" : "b355c569efcd409e252ccbb500d9fc2713b4d64d",
"version" : "0.12.5"
}
},
{
"identity" : "skeletonui",
"kind" : "remoteSourceControl",
"location" : "https://github.com/CSolanaM/SkeletonUI.git",
"state" : {
"revision" : "f025e9ba5d051374d7344efa8859df5b9399a181",
"version" : "2.0.2"
}
},
{
"identity" : "spectre",
"kind" : "remoteSourceControl",
"location" : "https://github.com/kylef/Spectre.git",
"state" : {
"revision" : "26cc5e9ae0947092c7139ef7ba612e34646086c7",
"version" : "0.10.1"
}
},
{
"identity" : "stencil",
"kind" : "remoteSourceControl",
"location" : "https://github.com/stencilproject/Stencil",
"state" : {
"revision" : "4f222ac85d673f35df29962fc4c36ccfdaf9da5b",
"version" : "0.15.1"
}
},
{
"identity" : "surveymonkey-ios-sdk",
"kind" : "remoteSourceControl",
"location" : "https://github.com/SurveyMonkey/surveymonkey-ios-sdk.git",
"state" : {
"revision" : "23252ff304950bc3b78cb6c0d91e15cda6cc7a93",
"version" : "2.1.3"
}
},
{
"identity" : "swift-argument-parser",
"kind" : "remoteSourceControl",
"location" : "https://github.com/apple/swift-argument-parser",
"state" : {
"revision" : "c5d11a805e765f52ba34ec7284bd4fcd6ba68615",
"version" : "1.7.0"
}
},
{
"identity" : "swift-asn1",
"kind" : "remoteSourceControl",
"location" : "https://github.com/apple/swift-asn1.git",
"state" : {
"revision" : "810496cf121e525d660cd0ea89a758740476b85f",
"version" : "1.5.1"
}
},
{
"identity" : "swift-collections",
"kind" : "remoteSourceControl",
"location" : "https://github.com/apple/swift-collections.git",
"state" : {
"revision" : "7b847a3b7008b2dc2f47ca3110d8c782fb2e5c7e",
"version" : "1.3.0"
}
},
{
"identity" : "swift-custom-dump",
"kind" : "remoteSourceControl",
"location" : "https://github.com/pointfreeco/swift-custom-dump",
"state" : {
"revision" : "82645ec760917961cfa08c9c0c7104a57a0fa4b1",
"version" : "1.3.3"
}
},
{
"identity" : "swift-package-manager-google-mobile-ads",
"kind" : "remoteSourceControl",
"location" : "https://github.com/googleads/swift-package-manager-google-mobile-ads.git",
"state" : {
"revision" : "32c61bd35c10517bb9d1d28252af71fe7fd3d0c8",
"version" : "12.13.0"
}
},
{
"identity" : "swift-package-manager-google-user-messaging-platform",
"kind" : "remoteSourceControl",
"location" : "https://github.com/googleads/swift-package-manager-google-user-messaging-platform.git",
"state" : {
"revision" : "13b248eaa73b7826f0efb1bcf455e251d65ecb1b",
"version" : "3.1.0"
}
},
{
"identity" : "swift-protobuf",
"kind" : "remoteSourceControl",
"location" : "https://github.com/apple/swift-protobuf.git",
"state" : {
"revision" : "c169a5744230951031770e27e475ff6eefe51f9d",
"version" : "1.33.3"
}
},
{
"identity" : "swift-snapshot-testing",
"kind" : "remoteSourceControl",
"location" : "https://github.com/pointfreeco/swift-snapshot-testing",
"state" : {
"revision" : "a8b7c5e0ed33d8ab8887d1654d9b59f2cbad529b",
"version" : "1.18.7"
}
},
{
"identity" : "swift-syntax",
"kind" : "remoteSourceControl",
"location" : "https://github.com/swiftlang/swift-syntax",
"state" : {
"revision" : "4799286537280063c85a32f09884cfbca301b1a1",
"version" : "602.0.0"
}
},
{
"identity" : "swiftcheck",
"kind" : "remoteSourceControl",
"location" : "https://github.com/typelift/SwiftCheck.git",
"state" : {
"revision" : "077c096c3ddfc38db223ac8e525ad16ffb987138",
"version" : "0.12.0"
}
},
{
"identity" : "swiftgenplugin",
"kind" : "remoteSourceControl",
"location" : "https://github.com/SwiftGen/SwiftGenPlugin.git",
"state" : {
"revision" : "879b85a470cacd70c19e22eb7e11a3aed66f4068",
"version" : "6.6.2"
}
},
{
"identity" : "then",
"kind" : "remoteSourceControl",
"location" : "https://github.com/devxoul/Then.git",
"state" : {
"revision" : "d41ef523faef0f911369f79c0b96815d9dbb6d7a",
"version" : "3.0.0"
}
},
{
"identity" : "uickeychainstore",
"kind" : "remoteSourceControl",
"location" : "https://github.com/kishikawakatsumi/UICKeyChainStore",
"state" : {
"revision" : "8220ac38124613fb709508426f75fbac6921e261",
"version" : "2.2.1"
}
},
{
"identity" : "uid2-ios-sdk",
"kind" : "remoteSourceControl",
"location" : "https://github.com/IABTechLab/uid2-ios-sdk.git",
"state" : {
"revision" : "f6f4ee78a03b5cd08f24a31444ff8b7ea06be476",
"version" : "2.0.0"
}
},
{
"identity" : "vcrurlsession",
"kind" : "remoteSourceControl",
"location" : "https://github.com/plu/VCRURLSession",
"state" : {
"revision" : "719d9796238dd6c431dbb29f2107ec5b5e668b3d",
"version" : "2.0.2"
}
},
{
"identity" : "xctest-dynamic-overlay",
"kind" : "remoteSourceControl",
"location" : "https://github.com/pointfreeco/xctest-dynamic-overlay",
"state" : {
"revision" : "34e463e98ab8541c604af706c99bed7160f5ec70",
"version" : "1.8.1"
}
},
{
"identity" : "zeotapcollect",
"kind" : "remoteSourceControl",
"location" : "https://github.com/zeotap/ZeotapCollect",
"state" : {
"revision" : "3d5d4eb89db67d92b49be3dc64deab513c90e0d0",
"version" : "1.3.10"
}
}
],
"version" : 2
}

```

### If using CocoaPods, the project's Podfile.lock

Expand Podfile.lock snippet

```yml

Replace this line with the contents of your Podfile.lock!

```

Start by reading RCNConfigRealtime's retryHTTPConnection method and its _isInBackground state handling. The issue provides no reproduction steps or test file, so inspect the Remote Config realtime connection flow and existing background-transition coverage. Done means the reported background connection attempts and resulting FIRRemoteConfigUpdateErrorStreamError events are addressed, with regression coverage if the behavior can be reproduced.

Written by the indexing model from the issue text.