Hello. I think that Jack integration could be easyer in next versions of Audacity. Here Jack Ports are created when audacity plays the file, and they are removed as audacity stop the play. It’s not really usable, because the user dont have any time to connect this ports to others than system output ports, and also, working on the Jack sound server has no utility. I think that jack ports should be created as the tracks are created (one port for one track), also we could connect them to what we want as we want, as in Ardour for example. What do you think about?
However, it’s probably not easy to “fix” and there are very few Linux developers working on Audacity.
To work around the problem, use the device toolbar to select the connections.
If you add any new ports (open another program), use “Transport menu > Rescan Audio Devices” to make Audacity aware of the new ports that are available.
Caution: Save your work before rescanning. Audacity is a bit prone to crashing directly after changing the audio system, particularly if you activate the recording meters before recording.