[Solved] Going off path like crazy

I’ve been up and running for five days and I have made some projects with success. Yesterday I ran Carmichaels guitar neck (from the project page in Easel). Everything went well but suddenly I heard something went wrong - I rushed to the machine and saw it had gone off path. Today I started over with the neck again and everything went as expected for two hours - then it went all crazy and took totally wrong paths. I would say it’s related to the Y-axis steppers but I have checked all connections - and double checked (and I will do a triple check).