Hello @emcentee ,
You need to withdraw from the beta from Samsung Members -> Settings -> One UI Beta Program Status -> Withdraw. Then plug the phone into your PC ,open up the PC version of smart Switch. Be sure to back up your phone since downgrading requires a factory reset.
Unfortunately , Good Lock features are limited during a Beta Program. But if you are facing an error with system, You may try backing up your device and performing a master reset which often helps with crashes.
One UI Beta Team.