If your microwave continues beeping after you shut it off and open the door, it is likely due to a safety feature known as a "beeper reminder" or "end-of-cooking signal." This feature is designed to alert you that your food is ready or the cooking cycle has finished.
The beeping sound is usually programmed to occur at regular intervals until you acknowledge it or open the microwave door. By doing so, you confirm that you have heard the signal and are aware that the cooking process is complete.
If the beeping persists even after you open the microwave door, there might be an issue with the control panel or the microwave's electronic system. In this case, it is recommended to consult the user manual of your specific microwave model or contact the manufacturer's customer support for troubleshooting assistance.
It's worth noting that some microwaves allow you to adjust or disable the end-of-cooking signal. Check your microwave's user manual to see if it provides instructions on how to adjust the settings to your preference.