Being an avid user of my AirPodsPro for commutes, working out and just taking calls in general, I figured that the constant noise cancellation, and tight seal in the ear canal, might cause tinnitus.
I haven't experienced any symptoms yet but I fear that prolonged use will further highten the chances of such a diagnosis. I'm sorry to hear that you might be experiencing tinnitus from AirPodsPro use, but I can't say that it haven't cross my mind, that it would lead to that.
This is just a thought, but I pondered that the noice-cancelling is further worsening ear health. I'd argue that AirPodsPro NC causes this because it feeds additional sound in (ie. cancelling) which takes an extra toll on your hearing. Again, just a thought. I have no science to back this up.
I've stopped using them in favor of my over-ear VModas the past couple weeks and my tinnitus is significantly better. I rarely listen to music loud and the volume only seldom goes over 50% so I'm having a hard time attributing it to excess listening volume.
[0]: https://discussions.apple.com/thread/250886390