Left Earbud Disconnecting After a Few Minutes

My left earbud keeps disconnecting on its own. I noticed through the Galaxy Wearable app that this side is consuming more battery than the right one, but the battery doesn’t actually drain completely, it just turns off suddenly.

When I place it back in the charging case, it works again, but only for about 3 minutes before disconnecting once more.

I checked the charger, and it’s providing the correct voltage. I also tested the earbud’s battery, and it starts at 3.7V but slowly drops.

Does anyone have any idea what could be causing this? I have some basic tools but I’m not sure how to perform more advanced testing. Any suggestions would be appreciated!