Big Sur doesn't boot anymore after upgrading to OCLP 2.3.0

Apparently it's a known issue. Loading the OS stops after a while.
Don't know if it has been fixed with version 2.3.1 but I need help going back to a previous state.
No backups.
Didn't find a fix for it yet and the OCLP troubleshooting guide doesn't help.

Thanks.