Follow the grill and accessory instructions. Covering a grid or collection area can change drainage and heat exposure, even if lining part of a pan is permitted.
What the observation means
Fat needs to collect as the design intends. Loose foil can move or approach hot components. A cleaning shortcut must not obstruct ventilation or create an unstable cooking surface.
A useful next step
Use only an approved arrangement and keep foil clear of heat sources. If smoking increased after lining the pan, stop and allow safe cooling before removing it. Do not use foil to shield a suspected faulty part or redirect grill heat.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.