Why are only a few of my Pages documents being shared across devices?

I've got ~30 Pages documents scattered around my desktop. Pages and iCloud are all set on share etc. across my iCloud account and two devices. Yet only a couple docs are showing up. I am trying to access several, and if the channels are open, then shouldn't they all be available across selected devices? Why are only one or two appearing? I tell you this is a very flawed tool, this whole iCloud sharing. It seems to work half the time. Don't get me started on this community support platform. Not even sure if this is posting to the relevant category. Pardon my digression. Thanks for any tips.