That is it - thanks @raino! I really appreciate you sharing the Listen workaround, I shall try that.
I will also say that while this technically makes sense, I would argue it disregards user intent. When I hit the Solo button, I … mean it. So I would have expected Cubase to be smart enough to ignore any mute (and just mute, no other) automation on that track when Solo is engaged, and re-enable that mute automation when I un-Solo that track.
So, maybe we need a “Solo, but I really mean it” button?!