Playback sound

Dear forum,
I am trying to play back my score using my bluetooth speaker.
The speaker is connected and working, because if I play something on youtube, it comes through the speaker.
If I press the play button on Musescore, it only comes through the computer speaker, which is faulty and buzzes.
I have gone into laptop preferences/sounds/select the bluetooth (Bose) speaker,
but this makes no difference to the playback in Musescore which reverts to the laptop speaker.
I have searched through the Musescore menus to see if something needs changing in the settings, but
cannot find anything in the handbook, or browsing the various buttons in Musescore.
Is this a bug, a one off to my computer, or have I missed something somewhere?
Nick