Propane tanks have an excess flow check valve that closes to prevent dumping a full tank in the event of a hose failure or fire. These same tanks also have a float that shuts off the flow of propane into the tank to prevent overfilling. I suggest you remove the tank you just filled and while holding it vertical, thump it smartly on the ground a few times. This will hopefully unseat a stuck float valve. When you reconnect the tank, open the outlet valve on top of the tank VERY slowly so you don't trip the excess flow valve. If neither of these 2 fixes work, see if you can temporarily borrow a tank and try that.
2015 Rockwood Ultra Lite 2604 WS. Rear LR, large street side slide with small wardrobe slide in BR.
2014 Ram 1500 Eco Diesel Laramie Quad Cab.