This feature extends the play time of your Melomania 1+ earphones by automatically swapping which earbud is directly connected to your mobile device (this primary earbud's battery drains more quickly then the secondary earbud). This happens when the difference between the battery levels of the two earbuds exceeds twenty percent. If you are listening to music when this happens you will notice your buds disconnecting briefly and then reconnecting again.
If your device is an Android TWS+ phone then the battery drain will be similar for both earbuds and so you should not experience this connection swapping.