That's interesting that it was an OS bug. I experienced a lot of those with this machine.
Apple support always asks ARE YOU ON THE NEWEST VERSION????? But then we introduce even more problems by upgrading. This is why I updated to 12.0.1 because newest is ALWAYS best... right? (It solved exactly zero of the issues I was experiencing).
I actually returned mine as well. But this was probably the smallest on a very long list of issues I had with the OS - especially when it came to a similar category of problem: the OS not working well with the hardware, most notably with the notch.
I wouldn't call yours a lemon, iburdeinick. It sounds like Apple is pushing forward too fast without making sure the software is stable. Later in the OS' life it'll probably be much more solid and if I ever do attempt an upgrade in hardware I'll wait much longer for the software to mature first.
Keeping my 2019 i9 instead. I found that after two weeks of testing, the upgrade was not worth the hassle. The "old" 2019 charges fine now that the entire logic board was replaced including the (defective from day one) USB C ports and has a rectangular screen. Rectangular screens are very underrated...at least until the software catches up with the hardware.