Mainstage Audio Cuts Out

MainStage Audio is randomly cutting out. It's fine for a while, and then suddenly there's no sound. I can see MIDI notes being played, but no output is registering on any of the meters.

I'm connected via Thunderbolt to an Universal Audio Apollo Quad interface.

Quitting and restarting MainStage fixes it, but then it cuts out again a little while later. Also, switching the interface off in audio preferences and switching it back on again fixes it. All software is up to date.

2022 Mac Studio M1 32 gb RAM

Mac OS 13.2.1

UAudio Apollo Quad 10.2.2

Mainstage 3.6.3

Please help! Mainstage is unusable like this.

Thanks,

Joe