Restarted 5 times since the update - some apps are unreachable while others are working just fine even though the Apps menu says everything is running just fine.
I updated once after installation from TrueNAS-SCALE-22.12.2 to 22.12.3 and restarted nas.
Then they were present again and working as before.
They were all truenchart apps. Five reboots is a lot though.