May not apply, but wanted to post on the off chance it helps. Had a GFC in the galley area that kept tripping, the “string” was a GFC right at the entry door and then an outlet in the galley, another outlet in a storage bay underneath the galley, and then the outlets in the bath, basically, the run went from the front of the coach to the back opposite corner. I noticed the issue one AM trying to make coffee, the outlet in the galley wasn’t working.
Initially thought it was the GFCI as it wouldn’t reset, tried replacing but no help. Tried replacing the downstream outlets, no help. Had a buddy come over (former engineer and far better electrician skills then my basic DIY ones). In the galley under the drawers was a junction box where the GFCI was connected to the outlet in the galley and then the downstream ones. The romex coming out of the junction went across the “floor” of the drawer area and then made a 90 degree turn “up” where it entered the wall and went to the galley outlet. That piece of romex was cut a little too short during install, very little slack (read none) where it made the 90 degree turn into the wall, it had rubbed the wall over time eventually causing a short in the wire, the GFCI was doing its job.
Replaced the romex with a longer piece and rebuilt the junction area, good as new.
Long shot, but if things keep tripping it could be the wires somewhere. Hope that helps and if not thanks for reading anyway!