one of three options
- sensor not detecting properly the transport path movement , dirty or displaced PH57A
- transport path skewed, possibly a gas spring damaged, you can see if the big transport unit moves properly parallel to the machine
- M55 motor not moving correctly but these steppers rarely fail, it's the driver module most of the times.
It appears to be the gas springs. They were not moving the transport unit up fast enough for the sensors liking. Both motors and boards seem to be working properly. Putting new springs in today and will give an update later.