You are indeed correct -- in that the magnets of the purple cover are supposed to click onto the cardboard cover of the waste trap. That way the purple cover lifts the poop compartment cover (sorry I don't have a more delicate technical term for that) and the poops are then swept under the cover. You can get the magnets to attach by pushing down firmly on the purple cover until you hear them click.
If your purple cover hasn't been attached to the cardboard cover, it would be understandable that the poops would be blocked from going under the cover, as it is not lifting. And the front part of the cardboard cover should remain as it is -- at a downward angle. You should not be unfolding any parts.....
Now -- regarding the trap portion at the back end (inside the poop compartment). It is not designed for all the poops to be segregated and to into that trap. It is normal for some to remain in front of it -- as long as they are all collected under the cover itself, everything is working fine. The main purpose of the trap is to help reduce the amount of crystal sliding under the cover.
Hope this helped!
