The last statement was that the suction unit wasn't properly grounded (they did the install) and may have led to the mother board in the mill being damaged causing intermittent yet non-recurring errors.
No, but Adding ground wires from the chassis to the A axis motor will help the conductivity issue these mill are having, I recently replaced my A axis cable and the newer one came with a ground wire in the loom to ground the A axis. But nothing with the suction. LOL
I hope you also replaced the loom stanchion truss crown bolts (left and right). You know the old rule when working with truss crown bolts: "smooth side up".