You'd think installing Ubuntu Studio which has Ardour, Carla, Jack, Pulseaudio en Alsa drivers baked in, would mean starting with a system where they're set up to work in unison.
They are not.
A tutorial series on using #Ardour6 by Whanake:
https://www.youtube.com/watch?v=Dq6BfzYsc_M&list=PL98ZX0JQtKmdmZD4LmFyr7NWiKaSHChot