After I clicked on OK, at the very top of the BiaB Window, where it normally shows file information is Bar Settings: Patch changes. Style change etc., instead. This remains in place for that bar only. If I move the edit box to the next bar, this info disappears. Also, a little red line appears under the bar number, but only for that one bar.
That is all expected behavior, and indicates a bar settings change at that bar.
I'm not clear whether just this bar is the only one affected, or if it is all the bars after it as well. There's no box where I can indicate the number of bars I want this to apply to.
It changes until you change it back.
I have all the instrument tracks frozen. And I was just hitting "Play," not "Generate and Play."
You definitely need to unfreeze the track.
MIDI tracks can't change to RealTracks (and vice versa), as someone else mentioned. Style changes work MIDI <--> MIDI, RealTracks/Drums <--> RealTracks/Drums. Currently MIDI SuperTracks style changes are not supported, and I think that is what the main problem is here.