iPad pro not sync'ing Pages documents from MacBook Pro pages

I have a 2013 MacBook Pro with High Sierra on it and a band new 2017 iPad Pro 10.5" with Smart Keyboard and want to use the two devices to switch back and forth between while editing the same documents.

That is, I want to be able to start a writing project on one device, close it, grab the other and continue working on the same document as was shown in the Keynote when iCloud and these devices were shown to do this.

Both devices are logged into iCloud under the same Apple User ID and Password. Both devices are on the same network (although the keynote did not show that was necessary between, Mac, iPhone, and iPad.) All devices are running the latest OS X and iOS and all devices are fully charged and working fine otherwise.

I have only a few days before I can't return my iPad Pro and if I can't resolve this quickly, I will return this nearly $1,000 devices AND I don't want to, I most earnestly want this to work (I'm a writer and I want to write on Mac, iPad Pro, iPad mini, and iPhone.

Thanks in advance to those who respond and help me figure out what I'm doing wrong.