Check for a loose connection in the electrical connector pins, one or two maybe not making good contact where it plugs into either of the two boards.
Here's the door wire harness for your model:
WD21X10545
If the door wire harness is good, then it has to be a faulty UI Board.
To verify that: Let's check voltage to the UI Board.
The UI operational voltage is output from the main control board on connector J722 pin 2 black/green to pin 5 yellow/blue. If 13.5 VDC is found here, then the UI Board is the problem.
Here's the user interface(UI) board for your model:
WD21X23461 Kit Svc Ui Top Logic
That J722 connector is on the other side of the control board, look here:
It's the one on the left above the ethernet port.
Let us know what you find.
Jake