Problems with Neff grill

I have a Neff HBT 554 oven with faulty grill and need some technical help.
FD number is 8204, ZN 801480

Tenant reported grill not working so tested element and found it had blown so replaced with new one.
The element has two tag connectors, and also two other pockets that receive a thermocouple and second one has loose wire ( presumably to thermal cut out?)

After installing new element the unit gets warm but does not reach full heat, regardless of setting of thermostat.
When switching to grill position the thermal indicator light flashes 5 times then goes out, even when set at max. heat from cold. Does this mean element is not reaching full power, or does it not show that way when using in grill mode.

Emails to Neff technical remain unanswered.

The back element in the oven appears to work ok, so I am thinking faulty thermocouple or a thermal switch, or main control board.

The back of the thermocouple is also connected to a switch and will test that when I return to the property to try to fix again.

Having invested GBP 85 in a new element I dont want to second guess what else may be wrong and considering abandoning in favour of new unit.

Element supplier will not accept a return even though the element has only been used for testing.

Thanks for any help to point me in right direction. I have not seen any parts on line that match what I have and do not have any manuals.

PS Cooling fan runs even when oven is cold at start up.

Thanks for any useful ideas!

Mod edit: have changed the word hob to oven to stop any confusion.

Don