We had the same problem back when we first got the coach and were stationary for 5 months. The level indicator in the propane tank stuck said we had 1/2 tank we ran out at 2 o'clock in the morning and 25º outside. That is when I got the extend a stay. and electric heaters. When I drove it to get the propane filled it then showed the correct level. I carry a rubber mallet now and tap the tank and that seems to work.
2011 Berkshire 390-rb-40, upgraded tires and front axle airbags, 2012 Jeep Wrangler 2 door, Blue Ox baseplate and BlueOx aladdin tow bar, Blue Ox Patriot brake system, wiring run through right frame rail and homemade led taillight bar.FB.