Pretty terrible situation. Tried installing big sur on my 16" MBP only to be stuck into a login loop that brings up the loading bar for a few seconds then restarts back into the login screen and then back into the loading page. Tried all the resets and nothing is working. Not only that but when I go into recovery mode I can't do anything because it says all my passwords are incorrect. Seems to be some admin password issue with big sur? So it's completely bricked my laptop right now. No idea what to do.