Odd bit of 3.6.1 behaviour. To recreate:
- Open an existing project.
- Tracks → Add New-> Mono
- Click on the track to select it (several times to make sure)
- Click the Recording button. An indicator should show audio being created, but nothing visual happens.
- Hit the space-bar to stop. The project will instead begin playback.
- Hit the space-bar again and re-select the mew mono track, then the recording button. Audio will be created as per normal.
Thanks folks.