I have been working on an app from last 8 months and we are testing it through TestFlight recently all of our previous builds turned into expired automatically (which is strange) even though the 90 days testing period for most of the builds was not passed.
And earlier this week we pushed another build to TestFlight which processed successfully but after a few hours of deployment it automatically turned into expired and after that, no tester was able to download it.
To fix it we pushed a couple of new builds to TestFlight by just bumping up the build versions, although now these two build didn't turn into expired but now all the testers are not able to download these from TestFlight and it prompts a message that "this requested app is not available or doesn't exist"
We are not sure if it's an error from our side or from apple.