ok, so I did a reboot and it didn’t come back 
My BT speaker turned from white to blue, Then with OSMC
I did re-connect, and that worked fine (blue turned to white on BT speaker).
But still no audio.
Eventually, I got it back.
But I needed to set the Audio back to HDMI, then reboot, then re-connect BT,
then set the Audio to Bluetooth.
Now it’s all fine again 