I find it interesting you describe the issue like that. I had my airpod pro 1st gens go out on me in a way that was very similar to that, with the popping noises as you walk and move around. I figured out that when I put them in “normal mode” i.e., totally disabling the noise cancellation microphone, it mostly went away. I just figured something had happened to/with the external microphones and/or the noise cancellation processing was not happening correctly. It was basically impossible to test this theory I had, but I wondered if it was an update that introduced a bug.

I can’t recall now at this point, but I do recall the feeling that the different ways I played with and tested to understand the cause and symptoms of the noise, left me with a feeling that it was not a physical/hardware issue.

I suspect Apple even knows, with as many problems they’ve had with the AirPod pros; but that’s another story… when they had to replace mine one bud at a time, about 6 complete sets, i.e., over about 10 replacements or so… during the pandemic nonsense.