A quick way to test if you have your Focusrite set correctly (to mono or stereo) is to run a quick test track into the other input, whichever is the "other one" from where you were plugged into when you didn't see the waveforms. I did that once, and felt really dumb after I figured it out.

Feeling dumb after I find something simple I was doing wrong is quite common here at Casa del Eastside.

crazy