Jennair JES9900BAS20 keeps blowing infinite switches on right front "custom control" element
I agree with Ecnerwal’s comment.
The element may ohm out good. 6-12 ohms or whatever the value but have a path to ground that you cannot see with a common ohm meter. In this case we would check the element hot to ground using a megger. A megger is a high voltage ohm meter I would be checking a heating element at at least 1000v. I would double check the wiring from the switch to the element.
As a megger will probably cost more than a element I would probably start by replacing the element itself if the wiring looks good.