Start by trying them on a second device, to verify it is the item, and not the source that is causing the issue.
If it persists, you may have a connection failure between the reciever end, and the other side. in which case, you would need to check the continuities between the wire going from the reciever, to the failing headset. if it fails, replacing that wire fixes the issue.
or you can save your self 3 hours of labor in a specialized niche repair, and buy these.
Start by trying them on a second device, to verify it is the item, and not the source that is causing the issue.
If it persists, you may have a connection failure between the reciever end, and the other side. in which case, you would need to check the continuities between the wire going from the reciever, to the failing headset. if it fails, replacing that wire fixes the issue.
or you can save your self 3 hours of labor in a specialized niche repair, and buy these.
https://www.amazon.com/LG-Electronics-HBS-750-Bluetooth-Wireless/dp/B00FO0IHMY