How could this happen?
Your device might be connected with the earbuds via 2.4g wifi. Since Bluetooth and wifi share the same antenna and work at the same frequency range, Bluetooth signals will be compromised when the wifi is tranferring a big amount of data.
How to fix?
A: Turn off wifi and try to pair again.
B: Reset to factory settings – Put the earbuds back to the charging case, long-press the button on the charging case for at least 10 seconds till the Led indicator lights flash – lighting always – flash – off.
Hope this helps. Good luck!