So when you turn on the ring is it not touching the underside of the hob top, Is this correct?
Ok they have fitted it wrong.
This isnt correct im afraid. When they have installed it they have more then likely fitted it onto the wrong step on the brackets in there so thats why it isnt touching the hob top.
So as someone has just repaired it then get them back in and they will refit it correctly for you again as this isnt correct.
Either will be able to do the repair. But if someone has just fixed it then i would get them back as they should do it free of charge for you.
I see the question is still open here. Do you still need anymore held on this?