It can interfere with clear contact or make control labels difficult to see. Cleaning must follow the appliance's instructions and take place under safe conditions.
What the observation means
A damp panel and a greasy panel are not invitations to spray liquid directly into controls. Use the approved cloth method once surfaces are cool. Abrasive products can damage markings or finishes and create a separate problem.
A useful next step
After approved cleaning, note whether the same control remains unreliable. Do not repeatedly operate a heater merely to test the panel. Record visible damage, uncommanded selections or loss of responsiveness for assessment, especially if the fault occurs during heating.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.