Ive been struggling with this issue ever since ive "upgraded" to the touchbar 15" from an old-school 17" fully loaded ( bluetooth 4.0 card included ) macbook pro .
After reading a **** ton about bluetooth, the only thing i could find is this :
- Every single apple device ( mouse / keyboard / airpods / etc ) uses a different bluetooth module than everyone else : A MASTER BLUETOOTH MODULE .
"Bluetooth networks (commonly referred to as piconets) use a master/slave model to control when and where devices can send data. In this model, a single master device can be connected to up to seven different slave devices. Any slave device in the piconet can only be connected to a single master. " - https://learn.sparkfun.com/tutorials/bluetooth-basics/how-bluetooth-works
What that means for the regular device is basically this : Every single time a master device needs to use the bandwidth , it pretty much screws any slave device and cuts in line.
To make things worse , bluetooth audio is extremely bandwidth hungry ( AAC is implemented in Apple products and there are a growing number of headphones that support this codec. It runs at 250kbps )
But wait ...theres more "great" news for the touchbar macbook : they switched the wireless module that was used in all previous versions ( the Broadcom one ) with : Murata/Apple 339S00056 Wi-Fi Module. Yes i know it shows up as Broadcom in the system report , but its NOT THE SAME CHIP. Comparing the 2011 mbp 17" bluetooth 4.0 chip with this new one gives the stark conclusion: its worse , way worse . On the 17" i could easily use a bluetooth speaker ( in master mode ) and my surface mouse ( in slave mode ) and the mouse would never disconnect / lag. Having the same setup on the touchbar made the mouse un-usable as it would stop - disconnect - reconnect after 2-3 sec.
And the cherry on top of this whole f**** thing is this ( taken directly from apple support website ) https://support.apple.com/en-us/HT203729
Bluetooth: Unreliable wireless performance may occur when USB 3.0 external devices are close
Yes, you read that correctly - USB 3 devices **** up bluetooth! ...on a laptop that ONLY HAS USB 3.0.
In conclusion , if you ever wonderd why the macbook pro has a headphone jack ? ...now you know : bluetooth audio on a $2000+ machine is "unreliable" due to "courage in removing ports "
PS : if you can find a bluetooth mouse that is "MASTER" ( not the magic mouse ) that looks and works decent , please let me know . So far both Designer and Surface mouse use the slave chip .