Thanks for the tips ZC.
Update--I just called PSI back and the agent said only a manager can reschedule me, call back 8 AM Pacific time to reach one. No other information or advice given on the status of the problem. I had to proactively *ask* for rescheduling. Otherwise, the tech agents did not offer any guidance. It seemed like they don't know what to do--can't blame them, I think CLARB just opted for the lowest-level budget testing service.
If that deleted post was true, it's pretty crazy that testing at the center itself is not a guarantee of smooth service.
To anyone else having these problems, don't give up, make contact with PSI and CLARB. Good luck everyone...
[forgot to post this earlier, this is a screenshot of the error, inaccessible LAUNCH button. It was the same screen even at 10:40 AM]