Leap has a major problem with bluetooth audio headsets. 
The current report is for a X201 Lenovo with BT3.0 adapter and a "Silvercrest
SBTH 4.0 A1" BT headset. It is also applicable for Pioneer BT models.

Bluetooth does pair correctly with these devices. 

However:

Once done the pairing, you get several, unpredictable and erratic results that
make the use of BT headsets useless. 
a) create several users. Login into various sessions. Choose a session for
pairing the device. You will find that: the device will pair but it will not be
available to that user. It will instead erratically be available to another
user. In my case there is one user that is always "dominant" as long as logged
in, steeling the device from the others. If not logged in another user gets
"predilected". In these users the device is functional. Even if you do
disconnect them and reconnect the user you wish:
the device will give feedback over the headset. But short after the headset
will be muted. The device is never showing up in the tray or in the settings of
kde. 
If you start up the system with the headset on from the very beginning then it
works. However the user you want to use the headset with must be the first user
to log in. 
b)audio profiles: when you pair a new headset device you will find that: the
audio profile hdp/hsp is defaulted. The sound is miserable. The A2DP profile is
selectable but no "apply" button is given (greyed out). The "OK" button is
selectable, closes the dialogue but the Headset defaults back to hdp.
You have to log out all users and restart the whole system. Then, when logging
in and after several tries it will be possible to switch to A2DP. There is no
prevision possible however when and why this will happen. Once it will happen
for that session the sound will be perfect, the headsets works as expected. 
Once logged out you run into the bug mentioned under point "a)". So again your
device becomes useless. 

c) Transport profiles: Several other BT limitations of the adapter itself
exist, profiles and the correct loading of them seem to be a prevalent issue.
The transport profiles are erratic, connecting to a PC works, you can send
files but you cannot browse the very folder you did send to afterwards, it
appears empty. 

I think that the errors reported here are a possible duplicate of Bug 974835 ,
as well as bug of Bug 961784