Different materials gain and retain heat differently, and their shape changes the food depth. The same dial setting does not guarantee identical timing or browning in both containers.
What the observation means
Heat-resistant glass must also be used within its own manufacturer's restrictions, including limits on sudden temperature changes. A dish suitable for normal oven cooking may not be suitable under a grill. Comparing the new result with an old metal tin is therefore a cookware question as well as an appliance question.
A useful next step
Follow the dish and recipe instructions together, and never expose unsuitable glass to direct grilling heat. Record whether the base, edges or centre changed when you changed the container. If the oven subsequently performs poorly with familiar compatible cookware too, include that wider pattern when requesting an assessment.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.