Propane Problem

could be oil in the gas?? Had this issue with a gas buddy heater

I also have to open the closest gas appliance (stove burners) for a couple seconds to get flow to my fridge, but that's only when I first open the tanks.

I have found that I need to open the valve on the 20# tank slowly when it is hooked up to my extend a stay on the coach. Especially if the lines in the coach have become empty.

safety valve on the tank is closed.

The hose connector on 20 and 30# tanks has to depress a valve in the top of the tank inside the valve, where the hose screws in, could that be your problem? With no hose connected you can open the valve on top of the tank and no propane will escape the tank.

When we "wintered over" here in Billings in a 1988 32 foot Suncrest Class A, I bought a 100 lb. bottle from Costco, and had a 12 foot hose made up by Tractor Supply. I used the regulator from the motorhome tank with the 12 foot hose to connect to the 100 lb. bottle. When I took the bottle to get it filled, I put the regulator back on the motorhome tank so the furnace could continue as needed. We had no problems all winter long.
Is it possible your two stage regulator doesn't have an output of 11 inches water column pressure?
Is there an electric shut off valve in the line somewhere that is connected to the leak alarm? (It should be on the tank, if there is one.)
Other than low pressure from the regulator I don't know what could be going on. We never had a problem like that.

Edit: When I had the house tank filled this fall, I asked the delivery guy if he could fill the motorhome tank for me. He was glad to! Check with propane delivery companies and see if any will do the same in your area

What are you connected to? I would make sure the regulator is correct.