But for some reason I tried actually swiping up on the airpods themselves, which will increase volume when connected to my phone. It actually worked! It didn't change the volume level as shown in windows (already at 100%), but I was able to hear much better. So it looks like actually changing volume on the airpods is independent of changing it within Windows. This may not fix your issue, but it's worth trying. I feel so dumb that I didn't think of this before. But I swear that until recently, I *could* control volume via the volume slider in Windows. I don't know what changed.