Hi there, and sorry for necrobumping the thread, but I think it's totally related and could be of interest if anyone faces the same issue.
First, my thanks to @[deleted]. Now I'm able to flawlessly connect my XBox One Bluetooth controller.
But I'm on a dead end here. Everytime the controller disconnects (I reset/shutdown the system, or I switch off the controller itself), I have to manually delete the device on the bluetooth adapter, put the controller on discovery mode and add the device as if it were new. And then it adds it (and works perfectly).
It's like it completely forgets the device configuration after it loses the connection.
I'm not on the PC now (at work), but I wanted to post it here in case someone sheds light about it.