Nothing has broken. When you have Crossplay switched off your queue times will naturally be considerably longer as you will only be matched with other players who also have Crossplay switched off. This is the way it has always worked.
This PTB was a very early test of somethign that was being worked on, to get some early feedback. Our Design Team will make changes based on that feedback and it's likely that if anything progresses it will need a further PTB on it.