Q " My mac-mini upgraded to Monterey 12.5 . . . "
A - this implies the computer was running an older version of macOS.
A - From what older pervious was the upgraded from.
A - Did the user have a Rescue Plan in place before the upgrade ?
A - In this instance - the trusty TM Backup could save the situation.
This comprises having 3 Backups using 2 methods and 1 Off Site incase of Theft, Loss or Natural Disasters. A Time Machine Backup is very useful and can be used to Revert to Previous Working macOS.
For addition purposes - two Tested Clones each to separate external drives. This is insurance incase the upgrades goes sideways. At least one Tested Clone and / or Time Machine Backup should be Off - Site