Ok, please let us know how it goes for you.
All of the wiring harnesses get individually tested and then the electronics enclosures get final tested as well. During that test we check for proper motor direction among other things. However, we use the same two motors to test all of our electronics boxes. So either we need to start testing the motors as well, or bolster up our electronics testing process. Looking forward to finding a root cause based on your feedback! If you wouldn’t mind, can you take some pictures with your cover off and post them here?