Safety first: Allow the oven to cool before inspecting the fan and elements.

Check fan operation: Ensure the convection fan runs smoothly in fan-assisted modes. Replace the fan motor if it is slow or intermittent.
Inspect elements: Look for uneven glow or dark sections on elements; replace if partially failed.
Use correct shelf: Follow the user manual for recommended shelf positions and avoid blocking airflow with oversized trays.
Rotate food: For very large dishes, rotate halfway through cooking to compensate for minor unevenness.

Oven temperature is uneven; one side of food is more cooked than the other.

Possible Causes