Fusion Page does not play audio

I can see audio waveforms in the Fusion Page but no audio is heard when I play.
If I return to the Edit Page or the Fairlight Page I hear audio as expected.
I am outputting via an Intensity Pro 4K card.
This happens with all clip types that i have tried.

When trying to view audio in Fusion Page for an .mts clip, again no audio is heard. However when returning to the timeline the space bar will not stop or start the playback an the playline moves randomly and uncontrollably. I had to shut down Resolve to restore normal behaviour.