I'm not sure, but I can offer a few hints/tips that might help, or maybe trigger a thought to help yourself. I hope one of these works. First, I'd ensure that they are all on the same Z-plane, because if their elevations are different, they won't join. You may want to change your fuzz distance to something small, instead of 0, because maybe the actually ARE very very slightly misaligned. Also, keep an eye on your command line for a hint.