If all of the failed outlets are in a slide out, then you should check the wiring harness and connections either side of the harness. Moisture buildup at the connections can sometimes cause a leakage path that then trips the GFI. A single GFI can control many outlets in an RV. But having said all of that, in my experience, the refer. is normally on a dedicated outlet and should not loose power along with other outlets. Any additional facts that you uncover could be really helpful.
Larry Day, Texas Baptist Men volunteer
'13 Silverado LT 3500HD D/A CCSB 2wd, custom RKI bed
'19 Starcraft Telluride 292RLS