This might be a stretch... but I'm just throwing out ideas.
One time I had a Holley electric fuel pump that would drop pressure... and then stop working completely when it got too hot (when sitting in traffic). It was like it would seize up. When I let the car sit for a while and let the pump cool down it would start working again.
One other idea would be to check the tension on the serpentine belt to make sure the belt is not slipping when the air conditioning compressor turns on, causing low system voltage.
It's no fun when you have glitches on a new build... but we've all been there
