I downloaded Xcode 14.3 and renamed it to Xcode_14_3 so I had both versions of Xcode on my machine... launched it... and the project worked. I then launched 14.3.1 and used the "On Disk" option of the project when it asked. No more live compile issue with AVKit or AVFoundation. It now works for me... Something must have got corrupted with the project files when I updated Xcode, not sure. Yes I cleaned, and built. Hope that helps.

I am having the same issue (but with an existing project), also happening with AVFoundation. It started not working for me this morning on a project that had no issues yesterday with it. Possibly something to do with System Maintenance? https://developer.apple.com/system-status/ I will try again later today, but any insight or suggestions would be helpful.