Macbook Pro won't load startup options

No. I'm still at 12.0.1. Thanks for the reply though.

The latest on mine was that after going through the infinite loops I described above, I shutt it down again, and then pressing the Touch ID did nothing. Thinking that maybe it somehow had a low battery (I leave it plugged in almost all the time so that really should not have happened), I left it charging for several hours, but Touch ID still did nothing. Then about 1.5 days later I opened it to find the dialogue for setting up the system. It said I needed to reinstall the OS, but then would not do that from Time Machine. I then told it to just restart from my hard drive, and it did!!

After restarting it said something about a bad extension that it said it disabled. I didn't nothing to cause this. No new OS install or software installs in general. So I have no idea what the bad extension might have been. Perhaps it tried to do the system software update you mentioned on its own? Makes me a little nervous about the hardware possibly being a little wonky, but not much I can do about it now since it's back to working as normal.

I've tried shutting down completely and trying again about 5 times.