My 8 month old Smeg Victoria TR93IBL cooker is showing a flashing E4 error on the induction hob. It flashes for a few seconds then goes off..I cannot get it it work

I’ve turned it off at the mains overnight and still no change.

This happened before a couple of months ago but after a few mins turned off it was fine.

I can’t find the answer in the smeg manuals. Please help