You still had an audio track (RT) hilighted, so that is the track it got generated on. You said to generate midi track on a highlited track.

This was a good catch, they probably should not allow that (gray out the option) or give a warning. That is not something most of us normally do, as evidenced by the fact it didn't get caught in beta testing.

Maybe they DO want it to be able to do that, and it's just something you have to be careful of.

In the mean time - Don't do that. Change the habit. And send a note to support so they have a clue it needs fixing.
If they can dupe it, it sounds like an easy enough fix. But only if they want to. It may be by design, but just needs a warning added.

I do not work here, but the benefits are still awesome
Make your sound your own!