This has me hopping mad! I've been a USAA member for a LOT of years (40+) and always had my TT insured through them. Now they're out of the RV segment and have partnered with Progressive for that. ...
The way I understand it, the truck policy will cover it to an extent. What that extent is I do not know. I wanted mine covered when it wasn't on the truck and to its total value, so State Farm added the camper as a rider to my truck and apparently that covers the whole shebang for like $8 a month. I now store it in a hangar and fear very little about the camper when it's not on the truck.