There is usually a thermal fuse / thermastat that can blow /go bad if the heat gets to high without proper venting to prevent a fire. If it does have one, it should be behind the back panel somewhere if you pull the over out and remove the panel.

It could be a bad relay going to the oven

It could be a burned out terminal on the terminal block that leads to the oven portion

The 240 breaker could be going bad, is there a second one you can swap in to try in the breaker panel? If it lost a leg, the stove may still work but over definitely wouldn't.

These are all just guesses to check, not sure for exact model.