I know some regulators can freeze up as we had some vehicles that were propane powered and at times in the winter we had to pour hot water over the regulator.
I NOW have a happy ending to my problem. I had a suggestion that I remove the tank and tap it on the ground as a check valve ball may have been sticking and then open the valve slowly. I just went out and removed my tank then banged it twice on the driveway. I replaced the tank in the RV, hooked up my pig tail, I then opened the valve slowly to make the regulator think I didn't have a broken line and the site glass on the regulator turned green. I then lite my stove top and furnace and all is well again.