I had something similar start to happen. After some research here, I decided to replace the pigtail hose between the tank and the cutover valve. That solved my problem.
Full-Time 2014 - ????
โNot all who wander are lost.โ
"You were supposed to turn back at the last street."
2012 Ram 2500 Mega Cab
2014 Flagstaff 832IKBS TT