Https://forum.lightburnsoftware.com/t/issues-after-9-15-software/42965?u=khlaserworks

Definitely 100% not a belt or mechanical issue
As I have had this issue for over 2 years. (with anything newer than 9.19)
And I have run the machine using the older version (9.19) without any mistakes in whatever I do for those two years.

Really appreciate all your help