A rounded wok may not provide the required contact, detection or stable support. A traditional gas-wok arrangement does not transfer automatically to a flat glass surface.
What the observation means
Some appliances have dedicated accessories or cooking areas, but these must match the model. An improvised ring can scratch glass or create an unstable load.
A useful next step
Use cookware approved for the hob and follow its placement guidance. Do not balance a round wok on unrelated supports. If the wok is compatible but heats unevenly, record its base size and the selected zone without using empty high-power tests.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.