I know this post is old but I did find how to make it work despite being on W10 LTSC that is why I post in case if anyone have the exact same problem.
The problem was the driver they gave me (shipped with the dongle in a little disc) with my bluetooth dongle, as you can see in an upper screenshot from December 2019, I only had "CSR radio bluetooth" opposed to everyone else having the windows drivers that I have now ! (minus the nefarius of course).
If anyone have the same exact problem as me, it's simple, just uninstall the shitty CSR driver, insert the CD, the installer is a uninstaller too so nothing to explain here.
After that I did go in this page(I don't know the english name sorry), and choosed the 1st option to search for new modification on the hardware and boom it did install me the windows bluetooth driver.
And the bluetooth I had was a cheap one the same as the screenshot of cnrez, you can see the disc under it too, and after installing everything work, usb and bluetooth, I have just one problem I did now saw in the Q&A, but I think I'll do another post for it.
Have a nice day