For some reasons, non-Apple apps are immediately closing, and the interface immediately returns to the springboard. Hard reset doesn't fix this, nor does restarting the phone. I'm using iPhone XS Max w/512GB. I've got 70GB free. This seemed to start shortly after synching my music, which takes up several hundred GBs of data. Apple apps all seem to open fine. Oddly, not ALL 3rd party apps fail to open. Those that were already open (in my case, Instagram, Antenna Reddit client) still open. But any 3rd party app that wasn't already open will immediately close, and the interface returns to the springboard.
Anyone else experiencing this, and is there any alternative to reinstalling? This also happened yesterday afternoon, and I had to reinstall iOS 13, and restore from iCloud backup. But the problem has returned. I could simply start from scratch, but if I can avoid that, I'd prefer to...