Just a thought - when the HVBJB fails, it also affects fast charging, as those are also used in this scenario. With all the errors they are seeing, can they verify that this is also not a problem?
I went out exploring DCFCing today and got the "Charge Station Fault See Manual" message at a Tesla station. The Tesla station was in FordPass and I was using the A2Z adapter. I thought I was doing it all correctly but according to the manual it's a cord or station fault. I will try another Tesla station another day.
After that I went to an EA station and it all worked perfectly at a rate of 135kW. It deducted my free points from the charging bundle balance correctly. So at least I know that DC fast charging in general works.