Your UB400 is excellent but your driver is not. It works perfectly with Windows Generic Driver. But when I installed TP-Link Driver in hope of fully utilizing your product, everything became funny.
Your driver kept equipment information for itself and pass only generic information to windows. For example, I connected my headphone model xxx via your driver. I could see in your application that the headphone model xxx was connecting via bluetooth correctly. But in Windows, it only saw a generic stereo headphone. Hence, Windows could not utilize this headphone to its full functions. But when I uninstalled your driver then used Windows Generic Driver, Windows could recognize this headphone model and knew that it was surround Headphone and can deliver the sound correctly.
If you are going to have a driver, it should make your hardware working in full function. It should not be a blockage nor bottle neck.