They can on some designs. A changing sound or intermittent glow is not enough to identify a failure when the chosen programme deliberately controls several heat sources.
What the observation means
Fan grilling aims to combine surface browning with circulating air, so its behaviour can differ from either ordinary baking or an uninterrupted conventional grill. The exact sequence is determined by the appliance. Watching a single moment through the glass can make an intended cycle look like an intermittent fault. What matters is the model's description and the actual cooking change across a normal programme.
A useful next step
Keep the function name, requested temperature and food position with any enquiry. If the meal burns unusually quickly, stop using that setting until you have checked its instructions. A repeated electrical trip, smoke or an abnormal mechanical sound needs assessment regardless of the mode; do not dismiss those signs as normal fan-grill cycling.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.