Can you give us a little more information other than X goes crazy?
I donít have one of these machines myself but do use an EPILOG at work from time to time.
It could be many things.
The stepper motor may actually be going bad.
The driver board could be the cause.
The motor cable to X stepper could be failing.-- If I remember correctly the Y motor is stationary and the X axis and motor rides on Y. meaning the X cable must see some flexing. This is my guess as to a failure point for the X motor.
I hope that helped.