It works. I've tested it.
I think the problem is people check as soon as the phone boots up. Be a little more patient.
The other problem is interference from other apps. Uninstall other kernel apps.
Another problem is apps like greenify and ...
I just got the xiaomi Pistons 3 earphones yesterday and got disappointed because the volume down button is not working. But after reading yesterday's update .08, it's now properly working. Special thanks to smartperson, Nathan, and Phil.