Its base may be below the zone's minimum detection size or lack the required magnetic construction. The pot's contents and overall height do not solve that mismatch.
What the observation means
A suitable small-zone option may exist, but its requirements are set by the model. An unapproved adapter can introduce different heat and safety issues.
A useful next step
Check both manufacturers' guidance and choose compatible equipment. Do not place loose metal under the pot or hold it against the glass by hand. A detection message with one tiny pot is different from every suitable pan being rejected.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.