Ballast overflow problem / question

Wondering if anybody else has experienced the following problem with their stock gravity 3 ballast system. It's new...and hasn't happend until recently. When filling the left and right rear tanks, instead of overflowing out the left and right thu hull fittings when full, the water back flows up to the ski locker bag and then out the ski locker bag overfllow fitting. It does this even with the switch for the center (ski locker) in the 'off' position.

I haven't trouble shot the problem yet but suspect maybe the spring in the sprinkler valve going off the manifold to the front bag is shot. I just don't get how it would be easier for the water to backflow from the back tanks all the way to the front bag, through the closed sprinkler valve, rather than out the open ended overflow connections on the rear tanks. Could the static head on those rear tanks overcome the pumping pressure of the rule pumps enough to push open the front bag valve? (I haven't removed any springs)

I have a 2007 Mobius LS has the Gravity 3 stock ballast system. Remember I have hard tanks in the back, not the bags. Any ideas where I should start?

Hey wakemakers.com.....do you have the three tsunami 800 pumps / spinkler valve replacement kit complete and proven yet?