I’ve been using iCloud for all my documents for the past year. In the past week or so there’s been a very noticeable delay opening/downloading documents. I tap and it seems to be at least a minute before a document even begins to download. Even saving a document into my main iCloud Documents folder has a delay before the file will appear locally.
Previously, with the same device (iPad Pro with LTE), this sort of thing was nearly instant excepting larger files.
Edit: Hmmm. Now iCloud files won’t even download. I get an error with helper application. Seems to be an issue just with this iPad. My iPad Air 2 and iPhone are accessing files normally. Anyone have any experience with this?