Every other prop nocollided when pasting in contraption via advanced duplicator

Title says it all, I open and paste in a contraption from advanced duplicator, and every other prop is nocollided with everything. What up with that? If it helps, the contraption is a roller coaster, so the first rail is nocollided with everything, the next rail is fine, next one is nocollided, etc. So, no rollercoaster rides for anyone. It’s not a small coaster, took twenty hours to build. I already tried exiting and relaunching the game, going to a different server, and reuploading a copy then opening the new copy. no dice. Thanks in advance for any help.