Updated to 12.1.1 a couple days ago, and I've had to restart the screen a couple times due to freezes. Voice commands don't seem to work either so I can't submit bug reports... Anyone else had these kinds of issues after upgrading to 2019.12.1.1?
I've experienced screen freezes related to both incoming and outgoing phone calls with my phone connected to Bluetooth; details here:
Bluetooth problems on phone calls only
In brief, Bluetooth phone calls no longer work for me at all, and some others have reported similar problems. Sometimes (but not always) attempting to place or accept phone calls via Bluetooth causes the Tesla's screen to go black, and a manual reboot seems to be necessary. Bluetooth still works fine for playing media, though.
I recommend doing some testing in a driveway, and if Bluetooth phone calls no longer work for you, disable Bluetooth for phone calls on your phone, to minimize the risk of crashing the Tesla's screen. (This problem doesn't affect all phones, though; some work just fine.)