I am leaning more towards my ballast valves could be bad and cutting on automatic now. I didn't have my fly high bag hooked up in the ski locker in the front and the door was shut while running the boat. That's my first guess at this point, but can't do much until I can get the boat back in the water at this point. I still have the Orbit valves that seems to cause a lot of issues for people. I might be experiencing this now. Might be time to switch over to the Irritrol 700 series valves.
This is probably a good guess...I don't know if I have bad valves too, but I have the same model and year Mobius as you, and the center ballast bag fills a little when underway, even though I never turned on the ballast switch. And +1 to what kaneboats said above.