I’m having a similar issue with iOS archiving. I opened a thread about it here:
The build and staging complete successfully, but the Archive fails during the “Copy Executable and Staged Data into .app” phase with a .app: Not a directory error.
I’ve also tested it with Unreal Engine 5.8.2, and unfortunately the same issue still occurs.
Since you were able to archive successfully with the new Xcode, did you encounter this issue at all?