If you are running already macOS Ventura (13.0+) you need to do following to be able to start Bisq:

enter following command in Apple Terminal sudo xattr -rd com.apple.quarantine /Applications/Bisq.app

hit enter and you will be prompted to enter your password to be able to execute the command as super user

After running this successfully you should be able to start Bisq as always.

If this procedure still does not allow you to install Bisq, a last resort workaround is to install Bisq in a Linux Virtual Machine running on your system.