During the Bluetooth playback, I can hear operation sounds or notification sounds from smartphones and other devices and playback is cut off

If there is a smartphone or other device connected by the Bluetooth function present along with the connected device executing the Bluetooth playback, you may hear the operation sounds or notification sounds from those devices.
If you hear the operation sounds or notification sounds from a smartphone or other device, disconnect the Bluetooth connection from devices other than the device used for playback.