We have the same problems. We are currently on our second main control box replaced by HW#H and still have problems. My mobile RV guy has troubleshot our original one and found it has a bad cold solder joint on a board even though HWH had repaired it twice and sent it back. It is on the bottom yellow "Chicklet" as HWH calls them on the right side of the box. we are to put in the third replacement box this Friday and if it doesn't work, he will just fix the cold solder joint on our original box. You might want to check for this.
Marvin & Donna C. with Lila (our dog & Third Musketeer) 08 40' MDTS Low Roof, 400 ISL, Towing 2016 Yukon XL Denali