Please try the following steps 

1. When connecting to a mobile device for the first time, there is a pop-up window for you to confirm pairing. Select "pair". If you select "cancel" accidentally, you need to delete the earbuds from the device's Bluetooth history and re-pair Liberty 2.

2. If you have only paired the earbuds with one device:
Stereo Mode: Take both earbuds from the charging case, they will automatically enter into stereo mode.
Mono Mode: Put 1 earbud into the charging case and close the case, then use the other one. If that one doesn't work, please confirm step 1 has been completed successfully.
When you switch from stereo to mono, the audio will pause. Within 2-4 seconds Life 2 earbuds will connect again so press play to continue listening.

3. If you paired the earbuds with several devices before, disable the Bluetooth on the other devices and connect the earbuds to the device you want to use. If the earbuds do not connect with the device automatically, you can manually select the earbuds in the device's Bluetooth menu. After this, follow the same method in step 2 to switch between mono and stereo.