24 digit recovery key?
Recently updated to Big Sur, no longer recognised as administrator. When I go into recovery mode, to add administrator, I'm asked for a 24 digit recovery key (not the 28 digit Apple ID recovery key). Is this File Vault as I've seen mentioned online? I'd never heard of it before, I look, and it is turned on. I can't turn it off, because I'm asked for my administrator name and password, which are no longer recognised.
Snake eating its tail. Any suggestions please?
Thank you.
MacBook Air 13″, macOS 11.6