Ballast not draining

[MSD]

First day on the water in our new (used )'17 VTX with low hours.  Great fun! When playing around with the ballast, I could not get the starboard aft hard tank or plug n' play sac to empty.  They filled ok, but would not empty.  The pump ran but no water was coming out after all other tanks emptied.  I read several threads that explained the float could just be stuck, which was the cast with the front tank (it said 75% full, draining, but no water).  I could feel the water in the plug n' play bag, which also said 75%full/draining.  After not being able to get it drained and wanting to ski, I disconnected the plug n' play connection and let it drain out  through the bilge pump.  Water came out both the hard tank and PNP bag.   

I assume the pump in and pump out  are the same, correct?  Any suggestions on how to troubleshoot and primary order of operations would be appreciated.