I started playing around with Arturia's Yamaha CS-80, which utilizes (polyphonic) aftertouch, for some classic Blade Runner pad movement.
None of my black keys would trigger aftertouch!
I opened up MidiView, and sure enough, every white key sends channel pressure messages, but NONE of the black keys do. I've seen a couple old Reddit posts about this from 5 years ago, and a couple users had exactly the same experience.
Is this perhaps a bug in firmware 0.5.9? A hardware issue?