Hi Guys
I have an Atheros QUALCOMM Bluetooth adapter on my laptop and I found after a long time that this method works. I was wondering if anyone has had this problem.
The problem is this:
1) pair speaker using Bluetooth successfully using the settings>Devices>Bluetooth window.
2) can't connect to speaker to get sound after pairing.

The Solution (strange but true)
1) remove the paired device in the Start>Settings>Devices>Bluetooth, remove device button on the selected device.
2) Close Settings window
3) type control in search bar and open the Control Panel
4) in the "Category" view Under "Hardware and Sound" select "view devices and printers"
5) Now Click "Add device" button
6) select your Bluetooth speaker from the box that appears
7) When Windows installs your device this method it will link the sound bridge which doesn't happen the windows 10 way.

try it out and let me know!