Experiencing issues such as no sound while using Multipoint Connection can be frustrating. Here are some steps you can take to resolve them.

1. Disconnect your headphones from your device and forget them in your device's Bluetooth records. Then, reboot your Bluetooth device.

2. Keep the headphones turned on and reset them by pressing and holding the power button and "+" button for 5 seconds.

3. Try using Multipoint Connection with two other devices if possible.

4. Upgrade the firmware to the latest version via the soundcore app.

By following these steps, you should be able to resolve most issues with Multipoint Connection.