A quick update on this: I've fixed an issue where I was providing an incorrect CMTimeRange via my AVPictureInPictureSampleBufferPlaybackDelegate, so frames are now rendering as expected in PiP mode. The question about whether we can get the camera to work in background mode during development still stands though. Thanks

An update on this: I'm installing Xcode via the AppStore and it's affecting both of my development machines - a mac mini and a macbook air. I tried a full uninstall and reinstall on the macbook air and it didn't fix the problem. I'll use the feedback assistant too - thanks for the tip abeulink!