I’m plugged into my Virus MIDI in, with Virus Control active in Ableton, which should route everything that the Virus gets directly into Live. Ableton has a MIDI in indicator, which is where I’m able to see that there’s no note on happening for certain notes. It’s theoretically possible, I suppose, but highly unlikely, that the Virus is somehow filtering certain notes out. If it were random I would think it more likely than the precise behavior I’ve seen.
Should I try the OS beta? Is it reasonably stable? I’ll try another MIDI interface, as well.