Hello, yes I think it may be a problem with the stove. I had that too. Parts in the oven were replaced and it worked. It was a short circuit somewhere, according to the technician.

The only solution is to replace the bulb with a new one. If it still doesn't work, the problem is with the oven. Note that this oven bulb is easily found in any Migros for 2 or 3.-.

It didn't work right away with my oven either. I had to screw the bulb in with some effort until it really made contact.