Turns out I was unknowingly doing it by moving the printer to add, change and fix things.
From the get go the bed seemed twisted meaning I had a diagonal high / low issue IE Front Right and Back Left much lower that Front Left and Back Right.
I replaced "Y" rails and shimmed them but still it's difficult to get a level bed. Then some weirdness. I have a mobile workbench to make things easy when working on them and when the printer was on that it was easy to get a level and the twist didn't seem as pronounced. Then putting the printer back to its desktop position problem comes back again.
We then had a "Eureka" moment when it became obvious what was happening and why the machine would suddenly go out of level.
My mobile work bench has 10mm MDF shelves which are supported by metal rails at the perimeter by about a 10mm lip. So a heavy item will make the shelf sag a bit in the middle and there in lies the problem.
Looks like the Pro X isn't 100% rigid and can sag and move out of alignment it you are not careful.
The solution was to use cardboard packing pieces under some of the corners of the machine and through trial and error I came up with a nice alignment that allowed me to level the bed easily without too big a difference in heights between corners.
- packing_to_level.jpg (113.88 KiB) Viewed 19851 times
wow,thanks for your feedback.