The chemical and affected area can explain relevant exposure without assuming a confirmed cause. Different products have different restrictions.
What the observation means
A surface mark, control fault and liquid beneath the hob are separate observations. Heating it again to see whether residue disappears can worsen the situation.
A useful next step
Retain the label and describe the timing. Stop use for electrical, structural or overheating concerns. Do not mix another product in an attempt to reverse the effect or hide the mark before an appropriate assessment.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.