Very strange. If you are handy it's time to take the valves apart to see what is going on. Maybe construction junque is keeping the valves from closing completely. The alternative is to go to your destination and hire a mobile tech to fix the problem that may be $50+ but the problem would be solved.
And it would be of interest to find out what the problem was. Lots of RVers post problems but very seldom post the solution after using all of our great advice.
Dick_B
2003 SunnyBrook 27FKS
2011 3/4 T Chevrolet Suburban
Equal-i-zer Hitch
One wife, two electric bikes (both Currie Tech Path+ models)