Finally got around to pulling the smaller band out of the box and trying it out. When I put it in, there was no click and I realized it could easily just slide right out. No matter what I do it won't click in. So I got my s0 aluminum and pulled the black band off it. The s/m cloud band DOES click into the s0... And the black sports band DOES click into the ceramic (although the clicks with all bands are far more noticeable with the aluminum - not sure if this is normal with the ceramic). So there is something about the combo of the shorter cloud band and the ceramic watch that is preventing a good lock. Hopefully it's just a matter of getting the band replaced but it concerns me for the long term. Reversing the top and bottom band doesn't help - doesn't lock in on the top either. Annoying!