Samsung oven doesn't stay hot after preheat is done

Hello. As the title states, my Samsung (NE59M4320SW) oven will reach its temperature during preheat but then is not able to maintain the temperature once preheat is complete. If I re-set the temperature it goes up again. I have to continuously do this to successfully cook anything.

I replaced the control board and can hear relays clicking on/off during preheat. Once temperature is reached, I do hear the fan turning on every now and then. Still does not maintain temperature.

Confirmed that the bake element has continuity and the temperature sensor resistance is good. The temperature is reading correctly during preheat and again when I re-set the temp.

Any ideas before I have to bite the bullet and get a new oven?