Solved - Route path is moving up gradually

[HaldorLonningdal]

Your motors may be underpowered?
The G-shield is max 2.5A (with active cooling)

Setting the stepper motor current limit

Recommended voltage setting then? FWIW, I only raised the voltage setting for the Y-axis motors. That seems to have cured the grinding noise and slightly-out-of-sync motion between the two Y-carriages.