Why won’t my AirPods Pro 2nd gen respond to swipe gestures for volume control?

There is a long list of similar complaints by others in Apple Discussions about this problem, but no solution.

My AirPods Pro 2 (A3047) do not respond to the slide control for volume. 

Squeezing works for Play, Pause, Reverse, etc. But I am unable to change the volume. 

Finger-swiping the stem — with and without thumb — has no effect.

Resetting the AirPods has no effect.

Yes, I have read Change the settings of your AirPods and AirPods Pro 

Yes, I have read How to reset your AirPods and AirPods Pro 

Yes, I have read Pause, skip, and adjust volume with your AirPods and AirPods Pro

And, yes, under ACCESSIBILITY, Volume Swipe is turned ON.

Has anyone found an answer?

[Re-Titled by Moderator]