For over a week now, I've noticed that the main scenario duty roulette will not pop in-progress runs.

I don't really run the main scenario daily anymore because I have a lot of other stuff to do, but FC members have asked me to queue into their runs missing half the people a few times. I go to queue for main scenario, since I figure I may as well get the bonus, but it won't pop until I queue without using roulette.

This is disruptive to players who are already in the instance, waiting for replacements which likely won't ever show up. Not many people queue for these dungeons without using the roulette since the amount of tomes they give are absolutely trivial now. It's fine if the group is mostly geared players, but for a group of mostly fresh 50s, this can make the instance very hard. This happens frequently, too. You can queue into in-progress praetorium as dps and almost always, there's an instant pop.