I read through this entire post and turns out I was having the exact same issue on mine, only on the left side. OF support had me do the same things but had no real results. I ended up loosening the 17mm ball screw nut on the front of the left Y rail about a quarter turn and it seemed to solve the problem for a couple months. The problem returned just recently and had a couple of lock ups and loss of position again. You mentioned that OF was taking care of the problem for you finally. Could you let me know what finally solves it? Thanks