Audio output only one channel

I have a strange issue with one piece: no matter what playback method or audio device I choose, it will only output the left channel. It’s not a panning issue at any stage of the playback, nor is it an issue upstream of Dorico (iTunes etc. working fine). If I start a new Dorico project, the audio is working fine with sound from both channels. Is there some way of resetting the playback for a piece?

I was able to get around this by copying and pasting everything into a new project.

In the future, you might try resetting the playback template in the play menu.