I can add audio tracks and connect the inputs to my interface until I import an audio track. After that, if I add a track and try to connect it in the matrix, the green dot will appear when I hover but when you click, it won’t connect. In some cases, if I arm the track, it is indeed connected but the matrix shows that it’s not. I’ve noticed also that when I import the audio track it automatically connects the input to my interface. This happens with the 6.9 bundle from Ardour and also 7.1 from the Arch repo.