TMCC Culvert Unloader not responding to CAB-1

My Command Control Culvert Unloader is not responding to the cab-1 when I press boost.

If I disconnect one of the wires going to the Unloader from my ZW transformer and then reconnect it while the moving part is in the middle, the motor goes on and returns to the starting point (just like it should do if I press aux1, 0.

Then I get no response when I hit boost or if I press aux1, O while moving part is other than the starting position.

Any suggestions?

Thanks.

Gary