Particles trapped beneath cookware can mark the surface when the pan moves. A clean hob alone does not prevent that contact.
What the observation means
A pan placed on a worktop or draining rack can pick up debris before returning to the hob. Dragging it increases the chance of damage.
A useful next step
Inspect and clean the cool base, then lift rather than slide heavy cookware. If the surface is already chipped or cracked, stop use and arrange assessment. Do not polish damaged glass aggressively in an attempt to restore an apparently smooth cooking area.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.