Kettle whistle kind of sound from AirPods Pro 3 left side - some kind of ear pressure fault?

Hello, I hope this post finds you all well.

Since this week I’ve noticed my left AirPod has been producing this incredibly loud whistling sound often. When it’s not, it’s either a faint airy sound, or a metallic ringing (that seems to amplify the sounds of my teeth and mouth).

I’ve heard some say this is a problem with ear pressure. When I close my nostrils and blow, the sound definitely changes, but never gets better - just pitch wise it changes.

Has anybody experienced the similar, and how did they fix it?

Thank you.

Also, for what it’s worth, I’ve had these 6 months.