I don’t know if this solution is universal and/or even permanent, but once I got back up to having 20GB free space (from 11GB), sudo and all other subsequent related user-password prompts started working again.
I don’t know if this solution is universal and/or even permanent, but once I got back up to having 20GB free space (from 11GB), sudo and all other subsequent related user-password prompts started working again.