Comment 28 for bug 1577197

in my case I have to do rmmod btusb; modprobe btusb

<rant>
it looks to me like every new release of Ubuntu manages to break Bluetooth audio in some way that is new and creative and ever-increasingly difficult to automate away:
 * 14.10 and before - volume wouldn't be restored, sink wouldn't switch; solved by having a script listen to dbus for a headphone connection event and tell pulseaudio to set the default sink and restore volume
 * 15.04 - no sound unless I disconnected and reconnected again; put that in a script
 * 15.10 - needed to connect manually, but at least the rest worked; solved by having a script look if the phones are connected, do a l2ping to see if they are available and connect; occasionally I'd have to rmmod btusb; modprobe btusb
 * 16.04 - this issue; I only managed to upgrade yesterday, I still haven't found a pattern to this madness
</rant>