I’m having difficulties with the looper function (using Ardour 9.2). When, during recording a loop, the playhead switches back to the beginning of the loop, the previously recorded underlying track is not audible. It becomes audible if I start afresh, recording a new loop over the top, but, obviously, that’s not what’s needed.
As to monitor settings: on the mixer strip I’ve tried with “In”, with “Disk”, and with both. As to recording mode, I am using “Sound on Sound”. In “Preferences” I’ve set “record monitoring” to be handled by Ardour.
I’ve tried both ALSA and Jack.
Ardour doesn’t really do “loop recording” in the main timeline (which is how I interpet what you’re writing about).
If you want to do multi-layerd “live looping”, you should use a plugin such as sooperlooper. Alternatively, explore the cue page for this, although I don’t consider this (or the equivalent in Ableton Live or Bitwig) to be the equivalent of a live looper.