Click is working, but no audio output from tracks/master

I can’t get audio output to work correctly in my project. I’m using an external audio usb (Alesis IO2 express) card with jack server.
When I record, the monitoring works fine (ie I can hear my instrument), but playback fails. Metronome is working fine.
It’s weard because the jack connections seems ok (
I tried with ardour 4 and ardour 5.

Any help would be really appreciated,

Easier to solve problems like this with realtime chat on IRC (links at the bottom left of this page). Tediously slow to resolve via a web forum.

Problem solved. I come from a cubase environment, and I was expecting playback to start as soon as the record button is untrigerred, but I have to stop and then play to get sound. Very stupid mistake.