That is a Jet-o-vator and not a Place diverter right?
Did the guy say where and what exactly he meant by the cable was "snapping"?
My diverter cable jacket had split where the crimped end piece is and I had no real control of my diverter.
Maybe he had a bad angle on the cable where it attaches to the pump arm?

Just a thought.
Edit: you replied before me.
I would think the cable should be as straight as possible as it goes into the arm.
Maybe it needs a different size cable to fit straight into the arm.