We read many comments about the issue to determine it was that pesky infinite switch. Looked up our appliance model and identified the switch part number needed and placed an order.
It did arrive five days later than stated but it arrived none the less.
To change out the switch took only a nut driver and Philips screwdriver.
Removed the front knob, removed the switch, and moved over the wires one at a time, one for one to the new switch. Screwed the switch back in and turned on the burner.
Shazam, that did the trick. It now operates the dual size and heat level.
Whole process took ten minutes.