Bluetooth - Paired but can't connect

[the_bertrum]

I do - there was no sound output if I changed it to Bluetooth (assuming this is for outputting audio via bluetooth to another speaker?).

Correct, that's for connecting Bluetooth speakers and headphones. That's why I though it best to check you didn't have it set.

After some investigation Windows also doesn't recognise moOde as an audio output device either, so (similarly to my S10) it will pair but not connect.

Might be a an issue with the BT adapter on your board. Could you use a different SD card with RaspOS on it and see if you can connect when moOde isn't in the equation?

There might be other less extreme things to try first though. If you wait a bit someone with more chops than I might venture an opinion.