Make the situation safe and follow the model's specific instructions for melted material. Do not improvise with sharp tools, solvents or cold water on hot glass.
What the observation means
The plastic type and affected location matter, especially near controls. Fumes or fire require their own immediate response.
A useful next step
Keep people away and allow only the cooling or removal method the manufacturer specifies. If you are unsure, leave the hob unused and seek advice. Do not run another heating cycle to burn away residue or cover the damaged area with a mat.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.