Our oven has been acting up for the last couple of months. I generally just use convection bake setting on it. It starts to preheat but does not reach its setpoint. Today I set it for 425F and it only reached 415F in about 40 minutes. Sometimes it reaches around 375F and then starts to drop. I have not used the broil or the regular bake setting in a while so don't know if they work.

The stove top works fine.

Any help would be appreciated.