I know you said that you checked the fuses, but did you check the trailer turn fuse? Most of our trucks have separate blocks. Since it's on the camper and the trailer, but not the truck, I can't think of any other obvious scenario.
'16 F550 CC, 4x4 with Link Ultraride air suspension, '18 AF 1150. Just so we can play with our snowmobiles, dirt bikes and fishing boat. And new 20' tag along...kayaks, bikes, mc's and extra water and food!!