My XCode 12.0.1 was not updated to 12.1 (there was a notification that there was not enough free space) - 35GB was available on the disk. In the end, I solved this problem by getting 45GB of free space and Xcode began to update. I think this is not a bug. If the App Store indicates that the size is, for example, 11.3GB, then this is only the package size. In reality, after installing Xcode, it takes a lot more. For example, I have 16.2GB of the application itself + 35.3GB of additional resources in the Developer folder (simulators, archives, etc.). 51.5GB! And updating and downloading an application is only possible if there is space to install the application, not to download it.

You don't need to deleted the tester, but simply terminate the build expiration date.

Enrolling in the Apple Developer Program as an individual Start enrollment Launch the Apple Developer app on the device you want to use for enrollment. Tap the Account tab. Sign in with your Apple ID. This can be different than the Apple ID signed in to your device, but must have two-factor authentication turned on. If prompted, review the Apple Developer Agreement and tap Agree. Tap Enroll Now. Review the program benefits and requirements and tap Continue.

So there is a bug. If, when uploading an application to the store, you checked the box to receive error reports, go to the organizer and see the reports on application crashes. The answer may be there.

You can ignore this warning. The app is loaded into App Store with this warning. It is related to the release of the new version of XCode (13.2). Update Xcode and it should be gone.