I never actually use unlocked orientation mode. It's normally just locked to portrait, but full screen video (YouTube, newpipe, etc) seems to temporarily override it (it automatically returns to portrait when I exit full screen). If I do need to go landscape then I'll tilt my phone and then press the rotate icon that pops up next to the android navigation buttons to trigger it to rotate to the current auto detected orientation but it stays locked and won't rotate back until I reorient and press the button again.