On my way to AS Service Dept in the a.m. with the same problem on my 2 mth old 20' FC 2017. Very first camping trip was a little over a week ago for 3 days. By the 3rd day, gradual loss of electrical although plugged into shore power at Corps of Engineers campground.
99% sure it was caused by defective wiring in 30 amp breaker at friends garage where We all gathered to organize the day before we left for the camping trip
Certified Electician met me at that garage today and found that 30 amp breaker was indeed wired "wrong" and my converter IS most likely damaged and I will be very lucky if that's the only item I will have to have repaired/replaced. I am sick!!! Also found out I was the first one to use this plug in this garage, but the RV utilizing the 50 amp out of the same breaker box experienced no problems. Glad for them
Not looking forward to what AS technician is going to find tomorrow, but it has to be fixed. Fingers crossed!