If the button on the charging case of your Xiaomi Buds 6 is unresponsive, please refer to the following troubleshooting guide:
1. Check the battery level of the charging case, because when the case is completely depleted, the function button does not respond to any press. The charging case powers off to protect the battery, and pressing the button will not trigger any action, including entering pairing mode or checking the battery level. Connect the case to a power source using a Type-C cable and allow it to charge for at least 30 minutes.
2. If the issue persists after performing all the above steps, please contact your local after-sales service center for further inspection, as this may indicate a hardware malfunction with the button or the charging case.