Please try one of the following options:
1. When the earbuds have connection records with multiple devices, they will prioritise reconnecting to the last connected device upon powering on. Please confirm whether the device you last used the earbuds with is the current device you want to connect to.
2. Once you've removed the earbuds from the charging case, the earbuds will enter a timeout state without connection if the last connected device is not found within one minute. To exit this state, place the earbuds back in the charging case, close the lid for 5 seconds, then reopen it to initiate a new connection.
3. Press and hold the function button on the charging case for 10 seconds or more to restore factory settings, then re-pair the earbuds.
4. If the above steps do not resolve the issue, please use the Nothing X app to download and update to the latest firmware and try again.
*All device customisations are integrated into Nothing OS version 1.1.4 and above. Please keep the Nothing X app updated via the Google Play Store.