Thermador simmer burners don't work

When I installed this oven (it was given to me) the front left x-lo burner did not work. Other 3 worked fine. Took it apart and checked the solenoid with a small screwdriver to check the magnetic field. Nothing on the front one, the rear was fine. Unplugged the wiring to check for voltage. The igniter went to ground and now no spark and no gas on the left 2 burners. There is gas to the right 2 burners but no spark. Could this be the re-igniter controller? The pots? The main controller? I’ve read most of the posts and am wondering which component it would be. Thanks for your help!:o