Synergy TT24 gray tank question

[KC8RXQ]

My 2016 Thor Synergy TT24 has an unusual situation that I would appreciate your comments on.

I realize that the gray and black tanks are small but it appears that the gray tank is way too sensitive to changed in fore/aft angle. If the vehicle is nose-down by as little as 1 or 2 degrees the tank will show 3/4's capacity with only 2 or 3 gallons of water in it. I have noticed that the shower drains very slow in this condition too and might even back up once the tank volume reaches a certain amount - again at that nose-down angle. Could this be a problem inside the tank or is this pretty commonplace with these Class C Sprinters?

Thanks!

Ed L
2016 Thor Synergy TT24