There’s a few things that could be.
First, from the video it looks like it’s just the left hand side of the X axis that is jumping, not the right?
Did you already take a close look to make sure there’s no clamp or bit of workpiece catching on the dust boot / cutter etc. when the machine is trying to come forward?
Try powering off the machine and then slowly moving the X axis all the way to the back and the front, it should smoothly move all the way, this will let you check if there’s any mechanical obstruction. If you do this too fast the stepper motors will wake up and start to interfere, you’ll get a lumpy juddering, just slow down, an inch every couple of seconds sort of nice slow move.
If that is OK, re-initialise the machine, keep the router over to the right and up at the top of the Z travel, try to jog all the way to the front, can it do that without getting stuck?
It is possible that the pulley on the left stepper motor is loose. You can mark up the end of the motor shaft and pulley to check this, see this post
If it’s none of that there’s more to try.