Need some 904 trans help

There is a fight going on in the VB. The governor is calling for a shift into 3rd. The valve responds. and the 2-3 shift is completed. Immediately the throttle pressure is sufficient to command a downshift, and the 3-2complies.The problem is the 2-3 shift valve is not supposed to do that. When it drops into drive, throttle pressure that was relayed around to the other end of the plug is supposed to be dropped out. For some reason this is not happening. Either the valve is sticking, is slow to move or perhaps the PT kickdown valve is interfering. In any case the problem is in the VB and I see it as the 2-3shift valve or the PTKD valve.
Stick around a bit. I'm not the brightest bulb in the economy pack when it comes to diagnosing Tfs. Hopefully someone brighter will chime in shortly.

EDIT
I was just checking out the FSM, and it occurred to me that the shuttle valve might be stuck. I think it is supposed to momentarily dump governor pressure during the shift. Hmmmmmmmmmmmmmmmm, I wonder.I have taken apart quite a few VBs with stuck shuttle valves.