Airpod Microphone muffled, and airpods won't reset
I recently bought a pair of second hand, brand new Airpod Pros. The sound is good, but when I leave voicenotes/calls, my voice is very muffled and hard to hear what I'm saying.
I have looked many online forums, and it says the main two likely issues are grit/dirt , changing the microphone setting to 'left' or 'right' ear only, or factory resetting them. Well, they are new, so there is no dirt from what I can see... I have already tried changing the mic to 'left ear only' or right ear, and it doesn't make a difference. And when I follow the steps to reset them, they simply will not reset - the light stays green when the lid is open. Setting them up on my iphone worked fine, so I don't think they are still connected to another apple account.
What could the issue be? I can't see any damage, they're in great condition. Is the fact that they won't reset related? I am unsure what else I could try, to make the microphone work.
AirPods Pro