A minute minder may only sound an alarm. It is different from a cooking-duration setting that is designed to end heating.
What the observation means
Look up the timer symbol in the owner's guide. An alarm that works correctly does not prove that an automatic stop was selected. Some ovens offer several timing functions on the same control.
A useful next step
Turn the cooking function off as required and check the selection before the next use. Report the timer mode, not just the number of minutes. Do not leave cooking unattended on the assumption that every countdown switches the oven off.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.