The issue you are describing did not happen in my Mohave testing. I will continue to test to try to reproduce the problem. Can you tell me from which version of MacOS did you upgrade to Mohave? E.g., Sierra, High Sierra, etc.
I did however see the “DPS is Installed but not available. Please cancel, reboot or try again” Error. I uninstalled, restarted and reinstalled DPS from fresh installation media to surmount this issue.
I will respond to support ticket now, but feel free to add your response here if you wish.