I noticed that from the factory one of the X axis pulley grub screws doesn’t tighten onto the D profile of the shaft. Maybe it was just a one time fluke, but in the official assembly video I noticed it was the same way.
To resolve this, just flip your pulley around and make the end flush like this picture. Also recommend backing out the grub screws and using blue loctite (Gel kind is the best). None of our pulleys had loctite from the factory even though we were told they would be.
In the future I’d like to see these pulleys be broached for the D profile shaft to ensure no pulleys magically roam about
Hope this helps someone, somewhere out there.