Files app, iCloud, Sharing

I have a MacBook Pro, OS 10.11.6. I also have iPad Pro & iPhone 7+, both iOS 11.2.

Yesterday when I copied the Documents folder into iCloud Drive, it was visible on the iPad & iPhone.

Today, when I added a folder from my Mac into the Documents folder in iCloud Drive, the new item was not visible on the iPad.

I deleted the new folder, and then copied a small txt file from my desktop. It is visible in Files.

What can I be doing wrong? How can I make iCloud Drive share Documents & Desktop?