Disconnect the belt and use the movement controls on the control panel to move the X-axis without any load. Does it move? You indicated in your first post that it moved freely by hand. If that’s the case and it’s “stuck” when powered (without a load), you may either have a wiring problem or a problem with the controller. There are four wires that power a stepper motor. They must be pulsed in a specific sequence. If even one of the wires is broken or has a corroded terminal (or the terminal has come loose - is it snug and all the way in?) then the stepper will appear to be “stuck”. It will vibrate in place yet turn freely by hand.
The simple test is to connect the extruder (the place where the filament enters the system) motor cable to the X-axis motor, then try to move the extruder motor via the control panel. As you do so, the X-axis should move. If it does, the motor is fine and your wiring has a problem.
In that case, thoroughly check the X-Axis motor cable starting at the motor and all the way back to the controller (you’ll have to open the case). The connectors at both ends should be tight and level (not inserted at a slight angle) and the cable should be undamaged.
For what it’s worth, I had a problem with my X-Axis a few months ago. The cable had gotten snagged on the extruder wheel and had been pulled out of the socket. The X-Axis cable also contains the X-Axis limit switch and because of that the cable didn’t simply drop out, which would have made it obvious. It was hanging from the limit switch. I’ve since been more careful about how I route my cables.
Since you have the same printer, it’s obviously possible this has happened to you too.