Flutter iOS app release build works as expected, but not when published to TestFlight?


I’m having an issue where the release build of my Flutter application works as expected locally, but when I release it to TestFlight it no longer works as expected.

I’ve built a Flutter application that uses Google MLKit’s Pose Detection API.

When testing the app via flutter run --release for iOS, everything works as expected. The same is true for running the built application (flutter build ios --release) from XCode, or using the release runner in XCode.

I’ve moved the built archive over to TestFlight, following the official Flutter docs, and it builds, verifies, and releases successfully. However, when trying to run the app, the pose detection model seems to work only once, rather than continuing to work properly in a loop as it has in all local versions. Note that the app doesn’t crash, it just doesn’t work as expected/as it previously has.

I’ve tried building multiple different times and ways, including not removing the Swift symbols, nor obfuscating my code. However, the problem persists.

More than likely this may be some error in my code, but I can’t understand:

  1. Why this is happening in release with TestFlight when it doesn’t happen during the local release build.
  2. How I can debug it.

Any suggestions would be very welcome!