Avoid sudden temperature changes to cold glass and follow the manufacturer's washing instructions. A shelf should not be treated like an ordinary room-temperature plate straight from the cupboard.
What the observation tells you
Its edges, trims and supports may also have specific cleaning limits. A rapid temperature change can stress glass, while unsuitable detergents or a dishwasher programme can damage some removable parts. Seeing that a shelf is glass does not establish its dishwasher suitability.
A useful next step
Remove it safely after arranging alternative food storage and let it reach an appropriate temperature before cleaning as directed. Inspect for chips before reuse. If a shelf is damaged, replace it with the correct part rather than attempting a food-area repair with general adhesive.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.