A904 reverse problem

Forward clutch is not releasing.
Did you air-test it before the VB went on?

If I'm right
This is probably the most common problem with do-it-yourself rebuild. One of the clutch plates, the last one in, probably did not engage the splines, and when you tightened the pump, it folded the plate over and jammed it up.
Try another air-test and pay attention to the sound as it releases compared to the direct clutch.
This is not the only possible scenario; just the most likely
If the airtest is good, then you'll need to study the VB looking for a stuck valve or a spring mix-up.