Leave the appliance cool and avoid scraping aggressively. Adhered material can be difficult to remove without damaging the surface beneath it.
What the observation means
Foil placed on the cavity floor may trap heat or violate the model's instructions. The next step depends on the affected finish and whether there is additional damage. More heat is not a safe general method for loosening it.
A useful next step
Check the manufacturer's advice for that exact surface and arrange assessment if removal is uncertain. Do not use acid, a power tool or an abrasive wheel. Explain where the foil was placed and which programme was running when it became attached.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.