Low volume level on bluetooth headphones

I have a 7th generation nano. When I first got it a year or so ago, I paired some bluetooth headphones and they worked fine. A few months back when I paired my Beats, the volume was low. I also paired my air pods and the volume is low. If I plug headphones in, the volume is fine. The beats are air pods work just fine with my iMac and iPhone 6s. There is clearly an issue with the nano and bluetooth that Apple should address. I have seen similar posts with no offer of a solution. I have tried resetting it and even restored to factory settings, still does work. :-(