Some models support showroom operation. Its presence and owner-accessible cancellation depend on the exact appliance.
What the observation means
This may be relevant after installation or a reset, but it is not a universal explanation for a hob that suddenly failed during cooking. Avoid service-menu sequences from unrelated products.
A useful next step
Check the manual for the displayed demonstration indicator. If it is not documented, contact support with the full model and message. Do not open the appliance or alter wiring because the controls appear active while cooking zones remain ineffective.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.