I was working on a file on my Windows computer over a number of weeks, which was stored in my iCloud account.
Today I went to open the file on my Mac computer and found what looked like a very outdated copy - many documents from the binder were gone. So I went back to the file on my Windows computer to see whether there was a problem saving the document (I still had the file open with the latest work open on the Windows computer)
I attempted to backup the document to my local computer in case there were problems with iCloud. This resulted in the same thing where a number of documents from the binder were missing. I did just a copy and paste of the project in Explorer, which did the same thing.
I then did a Save As with a different filename (to iCloud) and this time all of the documents were in the binder, but some of the documents were missing their information. More than half of the documents had their corresponding folders containing the .rtf files missing from the Files/Data folder. Once I had done this Save As, I then found that the open project on my computer has lost data from multiple documents as well.
I was able to export the documents to Word, expect for the documents that seemed to have lost their information (10 or so).
Fortunately I was able to find a auto backup that had saved all the information earlier which had the information for all the files that had lost their information (as they tended to be ones that I had written earlier in the process).
I have copies of what I attempted to save if you wish to see the files, I don’t know if that would be helpful to you or not.