The filament will only go by the gear if the extruder lever is released. But you can only get the filament to the right spot by having the lever pushed down. You want the power off so the gear will turn from the filament pushing by it. After filament is changed then home x and y, in this way it does not matter if they move. The printer knows where to go to. The problem with move while change theby Ericlkelly - Mechanics