Steam deck audio lock?

[boffer]

I play UFO 50 solely on deck, mostly docked to a monitor but often handheld.

The other day I unplugged from the dock mid game (main menu) to move to the sofa. Continued to play fine.
However now when I dock to my monitor, audio seems to be locked to the deck. Previously it would automatically route audio through the monitor, or headphones/speakers if connected.

All steam deck menu sounds still go to the correct audio output, as well as all other games but UFO seems locked to only use the steam decks internal speakers no matter what peripherals I connect to.

Obviously the monitors speakers not connecting via hdmi is one thing, but both wired and bluetooth audio not working through speakers OR headphones has me baffled.

Tried uninstalling and reinstalling the game also to no avail.