An accessory placed on the cavity floor can affect heat transfer and may be unsuitable for that oven. Check the appliance instructions rather than relying only on a liner's general advertising.
What the observation means
Some ovens contain a heating element beneath the floor; others have specific restrictions associated with self-cleaning or steam functions. A liner that covers an opening or traps heat can create a different issue from a dirty baking tray. The fact that it is labelled oven-safe does not establish compatibility with every cavity and programme.
A useful next step
Remove the accessory only when the appliance is fully cool and its instructions allow safe handling. Do not run a hot comparison with a questionable liner still fitted. Tell the booking team whether altered results or marks appeared after it was introduced, and retain the product details for assessment.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.