Hi Scott,
I apologize for the problems you have encountered. The current lab-based exam use an RDP connection to support the labs and use a higher number UDP port number that is blocked by some firewalls. A small percentage Pearson VUE test centers run into this problem. the RDP requirement also prevents the labs from working on macs, which is why we don't support Online Proctoring on macs at this time. We are working with Pearson and our vendors to move to a HTML lab interface to the lab that we expect will simplify and improve the lab connection. This should occur within the next month.
I'll reach out to you privately to see if we can find a proven test site near your location.
Sincerely,
Mark Stevens