Foam is cheap and forgiving. If you’re having a lot of trouble, troubleshoot with foam.
The 0,0,0 location isn’t determined by the computer, it’s determined by Marlin. Between steps 4 and 5, set the home location from the LCD or with “G92 X0 Y0 Z0”.
Does it happen after you finish one job and start a second job? But maybe doesn’t happen when you run the first job after powering Marlin?