I recently installed an Atlas crossing on my layout and noticed that my cars really wobbled going through the frogs (far more than they did through my Walthers turnouts). I know with turnouts you should bevel the point rails to improve operation. Is there anything analogous you should do with crossings to smooth things out?
Take one of your trucks off a car and run it through the crossing by hand. (push lightly.) Watch all the odd things it does.
What you may notice are:
the wheels drop into the gaps in the rails.
the guard rails don’t hold the wheels away from the corners of the rails.
the wheels may want to go down the wrong track.
You may also notice whether the wheels pick at the ends of the guard rails. (guard rails are the rails that the wheels don’t run on; they keep them going straight.)
After you look at this, think about what might help. I’ve had to add strips of plastic to the inside of the guard rails to make the gap narrower.