Comment by SCdF

From my experience it's not really an audio bug, it's a bluetooth one. (though reading other people's comments it also happens over USB as well?)

Basically, there are lots of weird race conditions and oddities in how they deal with communicating and syncing volume between the system and the bluetooth device.

This can manifest in your system volume saying one thing and your bluetooth device outputting at a different volume when you first connect, and then you do one volume adjustment and the bluetooth device will "snap" to that volume.

Another way is what the twitter post is about, where when you ramp the volume up or down, with at least some devices this appears to be done per speaker (so per ear), and they can get out of sync. Imagine if the increaseOrDecreaseVolumeBy(speaker: id, amount: int) function was blocking and didn't queue requests. If one speaker takes longer to adjust than another one (wireless communication being what it is), the slower one will drop requests on the ground and get out of sync with the faster one.