No sound (at all) in the right earbud of apple headphones(wired)

hi, all of a sudden i have a problem with my headphones (wired (the apple ones with the lightning)), specifically with the right earbud

it stopped working today for no reason, everything was perfectly fine before

everything is fine with the left earbud, but in the right one there is no sound at all, although the control buttons work fine

i hoped the problem would go away after i cleaned the headphones but it didnt

the wire and the port itself are perfectly fine too, there is just no sound in the right earbud for no reason

really hope it can be fixed

thanks!