Marlin will not allow you to move any further in a negative direction than your starting point until you've performed a home. I'm not sure if eliminating your end stops will get around this. I'd put the endstops back in play, enter a home command and trip each end stop manually to see if that gives you freedom of movement.
If you move your motors in a positive direction, can you then move them in the opposite direction back to their starting point - if so then that's normal behavior. If you can't move then back ever, then there is something else that's wroing.
If you move your motors in a positive direction, can you then move them in the opposite direction back to their starting point - if so then that's normal behavior. If you can't move then back ever, then there is something else that's wroing.