HI, I have tried all of your awesome fixes but the left earbud stopped working. As a matter of fact, the light on the left one does not light up all. Yesterday out of the blue it briefly worked. They have not incurred any damage.
What model are you referring to? Also, does it light up when in the charging case? And how long have you owned it?
Make sure that the left earbud’s battery isn’t completely drained. Sometimes, connectivity issues can arise when the battery is critically low. Charge both earbuds fully and see if the left one starts working again.