2021 Heartland Road Warrior 351. Four months old. Bath and half. Both front and rear dumps have worked perfectly until this weekend. Grey 2 showed 1/3 full and wouldn't dump. Black 2 dumps perfect. Front tanks dump perfect. I added extra valves to both front and rear to avoid the surprises we all seem to have experienced when pulling caps to install hoses. With my front main dump open, my Grey 2 is now dumping out my front dump. There has to be an auxiliary line in place for this right? I'm thinking some kind of blockage below the grey valve but above the Tee on the rear dump. We are leaving wednesday for a 10 day trip and I hate to head out not knowing the issue. Local dealer has been less than helpful.