OnePlus
Unpair a Bluetooth Device auf OnePlus
A OnePlus phone stores every Bluetooth device it has ever paired with, even after that device is switched off. This list is managed by the Bluetooth stack in Oxygenos, and each saved entry can auto-reconnect whenever the other device is nearby and powered on. That is why a headset or speaker sometimes takes over audio playback without being selected manually.
Turning Bluetooth off on the other device only pauses the link. The pairing key stays stored on both sides, ready to reconnect the next time both devices are active. To remove it for good, the device has to be forgotten from the connection list.
Open Open the Settings ➔ Tap on Bluetooth & device connection ➔ Tap on Bluetooth and select the device you want to remove. Open Open the device's settings, tap Tap on Forget, then confirm with Confirm with Forget device. The entry disappears from the list right away, and the phone stops trying to reconnect to it.
If you only want to stop the automatic reconnect temporarily, without deleting the pairing, switching Bluetooth off or using Airplane mode is the better option. Forgetting a device makes more sense once the pairing was a one-time use, or the other device changed owners.