WA help? Paid repair?

Have an Avid 48x96 Pro, mostly used for slab flattening but running into an issue that seems to be beyond me.

Left and right Y axis motors have trouble running parallel usually when they are at the far end of the table and returning to the home position. When this happens, the gantry gets stuck for a time on the y axis. Then the y axis resets to a new zero and starts its next pass from that new (wrong) point.

Tried troubleshooting with support but didn’t get far. Looking for someone who may be open to paid on site work to help resolve in Pierce County, WA.

Could be a belt is not tensioned correctly, the gear rack is extremely worn, or the steps per revolution somehow got off….

Can you say what you have done so far? Have you replaced all the wear parts? Etc etc