Its control may regulate heat rather than keep every element continuously energised. The exact behaviour depends on the selected mode and model.
What the observation means
A visible glow is an incomplete measure of the heat reaching the food. However, a new loss of cooking performance or uncontrolled heat is a separate concern and should not be dismissed as ordinary cycling.
A useful next step
Use the manual's description and record the control setting. Report a change in the food result alongside the observed cycling. Do not remove guards or use the maximum setting repeatedly simply to force a constant glow.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.