Yes I’ve been looking at things this morning I would believe that the shore power is good up to the power dog , so I was going to start at the breakers. I see it only has 2 breakers marked as 1 for the front ac and 1 for rear , I don’t see anything for a middle ac. So not sure where middle gets it’s power? But you say it shares power for washer dryer? Anyways all of the connections on the breakers seem tight don’t see any visual problems . And I have already lowered the ceiling mirrors to expose the front 2 ac to inspect wiring will let y’all know later. Just a thought the wife has been using the washer dryer at same time as the middle ac would this be my culprit as maybe I should cut the middle ac off when using washer and dryer?