Erase your M1’s internal storage in Recovery, reinstall macOS and you could see an error in which it failed ‘to personalize the software update’. That’s not easy to fix, as explained here.
DFU
macOS updates sometimes don’t work out right. What can you do to revert to the previous release? Did I hear you mention snapshots?
M1 Macs don’t use that warren of startup key combinations, but a logical structure of choices, mostly when starting up in Recovery Mode. Here are the full details.
The Eclectic Light Company 