Hello everyone.
I opened this thread two weeks ago and today i’ve update my box to the last nightly and check the Bluetooth but unfortunately still no working and It seems you couldn’t find a solution. 
I don’t know how help you to solve this issue, I’ve searched on the web and found some stuff In case it helps, here is it.
http://wiki.lemaker.org/LeMaker_Guitar:Bluetooth
https://patchwork.kernel.org/patch/10139577/
Thanks so much.