If you are here looking for a solution to fix the muffled sound from the right earbud of your Jabra Elite 65t, you are in the right place. I have gone through the same problem and was searching for a solution and came across this post. As suggested in the post I have taken a tooth pick and gently cleaned the tiny hole which you see between the 2 charging connectors and voilà it started working again.

NB: Please do this at your own risk