Smeg DO10PSS Cut-out problem

Hello again. It has been a while and last time I was here asking about an issue with this oven it all ended well.

The issue this time is that the main oven compartment started cutting out at very high temperatures (240C) a couple of months ago. When I say cutting out what happens is that the oven shuts down turning off all elements, circulation fan and display leaving only the cooling fan running. once the oven cools a little the oven pops back on and once the timer is rest all is well. We managed the situation by simply not turning the oven up so high – so not a real problem. However the oven has started cutting out at around 200C now – exact same behavio – this is now a much more impactful problem.

I have tried to debug the issue a little

1. The coiling fan still seams to be running OK – I can feel the air coming from above the door of the main compartment and it does not appear “weaker” than it used to.
2. I have heated the over up to various temperatures below 200C and the main thermostat seams to be working correctly (temperature light goes off when desired temperature reached etc).
3. All the over elements appear to be heating and the circulation fan seams to run OK

I have done some digging around in the various fora and it would seam that the “Thermal cut out” for the main oven may be faulty, but also that the cooling fan may be not cooling enough. Would greatly appreciate any advice as we like the oven and would prefer not to replace it if at all viable.

Once again thanks in advance

Mark