Some instruments not output sound to audio file

I’m trying to output audio but each time I do, one of the instruments is silent even though it plays in Dorico itself. I’ve tried reapplying note performer playback template, and checked nothing is muted or soloed in the mixer. Not sure what else to do, can you help please?

Are you exporting the same layout you use when playing the file in Dorico?

I’ve tried exporting the full score as well as specific layouts. Still the same problem.

Can you attach the project itself here, Louisa? Which instrument in the project sounds during playback but is excluded when you export audio?