Hi,
I've been much of the past several days corresponding with Serge, trying to sync attachments. Yesterday, I finally managed to get the Bookends folder to appear on the iCloud Drive. But, now I can't for some reason move my attachments from the Attachment folder to the iCloud Bookends folder. Whether I try to move 1 or 500, an icon with a slash through it appears. The size of my iCloud Drive has been expanded, too; it shouldn't be the problem.
Syncing Frustration
Re: Syncing Frustration
Here is some description of an icon with a slash from discussions.apple.com
A cloud with a single slash appears to mean that the item is ineligible and cannot be added to iCloud Drive because it does not meet one of the criteria for iCloud Drive files.