Well, I appears that the access to files in iCloud on a second computer has been remedied. Here's what seemed to work:
After following MD instructions on moving data files to iCloud, they would not open by simply using "open other" command until I tried the following: With the "open other" selection window open, I opened a finder window to the data files and double clicked to open them (one at a time of course.) Each file with correct pathway appeared in the File>Open window and they can now be opened at will.
(Posting was not allowed for awhile) @alexrose (not axlrose :-) )
That seems to imply that you have opened the file not the sync ability. This means you are opening the same files from two places on a network shared drive. This will eventually lead to corruption of your files and is HIGHLY NOT recommended. Do not open a file on the secondary computer, but select “NEW FILE” then select a sync file.
I would start over with a clean set of files. You keep talking about "moving" the files which implies that you are using the finder to move file which is problematic. This may seem to work for awhile until it doesn't.