@Tony Ok. Thanks for confirming.

@Tony Thanks for confirmation. Is there a way we can Identify what is the source of incompatibiltiy. As long as it is not hardware related, I'm hopeful can be fixed. To me it seems the UB400 is not...

@Tony 1) The headphones are not visible on playback devices. 2) Can you elaborate what do intend by disabling "inbuilt" bluetooth. Besides, I did a device manager comparison. - On my lenovo T470, PXC...

UB400 was recognized in Win10 plug and play. It was able to pair with Apple airpods. However it did not pair with PXC 550 headphones. Those were recognized as a Non-Audio device as a Bluetooth LE...