Unfortunately, the version of iOS can certainly have an impact on the behaviour of iCloud. Each version of iOS has a lot of under-the-hood differences that can affect the behaviour of system services like iCloud.
The Dorico folder does exist, but it doesn’t appear on your devices, and that isn’t a problem that we can solve directly, since the folder is created by the operating system and managed on behalf of our app.
Dear Daniel, I checked my “test” files. I could open a file on my Mac which was created on my iPad and saved in iCloud Drive. Unfortunately I wasn’t able to do the opposite - I can see files I created on my Mac and saved to the iCloud Drive on my iPad, but when I try to open them, I get an “Error opening file” message. Like I said before I am on a latest Versions of Dorico, macOS and iOS.
Does the Dorico folder appear as expected inside the iCloud Drive folder in the Files app on your iPad? If so, can you check that the files you created on your Mac are completely downloaded onto your iPad? You can force them to download by long-pressing on them and choosing Download from the menu that appears.
I really don’t understand, why the OS version should have an impact on this behavior. On all my devices, Ipads and Mac computers (I have a few), even with the latest OS, the Dorico folder in the ICloud drive doesn’t exist or, like you said, doesn’t appear, which at least means, that the files are not accessible.
Dear Daniel, thank you - your advice solved my problem. I see those files in Files App on my iPad which I created on my Mac. After I forced a download as you supposed, Dorico on my iPad works as expected. Anyway - some kind of not a very intuitive way:)