I'm having the same problem as well, with no fix in sight. I think it 's the dongle itself. This was being advertised as Bluetooth "3.0" when in fact, I believe it is USB 3.0... To explain, I have seen the following advertised.
"Bluetooth Adapter/Dongle 3.0 USB"
"Bluetooth Dongle v. 3.0 USB "
and a bunch of other permutations of the above. I believe these companies are purposely using the word order in the advertising messages and product name to market this item as a ....USB Bluetooth adapter/dongle with the supposed Bluetooth 3.0 protocol.When in fact, this item is still 2.1 protocols but USB 3.0 Comparable. The advertising is done purposefully this way to make people think they are getting something new and better.
I'm pretty sure this is just a marketing ploy (an effective one I admit) to get everyone to buy their device. Is yours dongle printed with a big overly conspicuous "VERSION 3.0".... 3.0 WHAT!!!!