Induction only couples to a magnetic pan that covers enough of the ring. Aluminum, copper, and some stainless pots will sit there looking innocent while the control flashes or shuts off. That is the cooktop working as designed.
If a pan that used to work on that same ring suddenly fails, then we talk elements and controls. Bring the pan to the appointment.
The pan is part of the circuit
Stick a magnet to the bottom. If it barely clings or does not cling, that cookware will not run. Warped bottoms that rock also lose coupling.
Size, material, and centering
A small saucepan on a large ring may be below the minimum diameter printed in the manual. Center the pan. Do not stack a wok ring and expect detection. Other zones working while one refuses is often size, not a failed cooktop — until you have tried a known-good pan.
When the zone still refuses
A flickering control after a boil-over, a crack in the glass, or every zone dead is no longer cookware. Dry the glass, check for a control lock, and stop using a cracked surface. Do not reach under the cooktop with power on.