Its condition and instructions need checking before it is relied upon. Regular use of the neighbouring oven does not verify the neglected cavity.
What the observation means
Stored items, contamination and unknown previous faults are relevant. A maximum-temperature run is not a general way to establish safety.
A useful next step
Remove only suitable loose contents while cool and check the owner's guide. Seek assessment for damage, uncertainty or abnormal behaviour. Explain that the cavity has been dormant rather than presenting its first failed use as a known sudden breakdown.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.