Sarena Oven heating issues

need some advice, I have a sarena sk312x and for some reason both my ovens are taking a long time to heat up, I have a fan oven and a conventional oven too, all elements appear to be working, but both ovens are taking nearly 30 mins to get to 180, once there thermostats seem to be doing the right thing turning elements on and off when needed, just takes a long time to get there.
ive done the following tests
VAC test tracing power supply right through the oven from mains to elements, all elements receiving 240v
continuity test on all elements, along with a resistance test
main oven element – 32ohms
conventional oven top element – 84ohms
conventional oven bottom element – 52ohms
I have realised I didn’t test the top element in the main oven but im not sure ive ever used it, does it come on in initial oven heating stage? I know the conventional uses both to heat up then just one to maintain the heat.
continuity test on all wiring circuits, only thing I cant figure out is the oven safety thermostats cant get a continuity reading from either but I am not completely sure how they work, plus my ovens are not over heating so im assuming they are redundant till then? plus my ovens are still heating which im thinking if they were faulty they wouldn’t do that?

ive used oven thermometers to assess the thermostats and they are not to bad when oven finally gets there, main oven is about 10 degrees out and conventional is spot on.

any ideas? im a bit stuck?