In my 2015 yukon XL I had a similar issue water was some how getting into the truck, the passenger floorboards always wet. I tried everything to find the leak, cleaned sunroof drains, etc, looked at AC coil nothing, taped up some holes in the fender by hinges, sealed around the battery area, so on.
In all of this I pulled off the passenger door sill and trim then lifted the carpet, in the floor rail there is a wiring harness and connector. It was full of water.
I never had anything short out but always on my mind when it would happen.
Maybe this might help your situation.