ONCE AGAIN - "Your eReader is not authorized to open this book"

This is soooo... awfully frustrating. Can't this actually be solved without workarounds (that don't appear to work)?!

I went through the following steps:

1. Delete the problem book(s) from your ereader.
2. Open Adobe Digital Editions on the computer. Check to see if you can read the problem book(s) in ADE. Connect your e-reader.  Erase authorization on ADE (Go to the Help Menu at the top). Erase the authorization for the ereader (go to the side menu of ADE). Keep the e-reader connected to the computer.
3. Go to your public library website and get a NEW book. Upload the new book to ADE. Adobe will then PROMPT YOU for the authorization. If it doesn't, go back to "help" at the top and reauthorize ADE. Go to the side menu of ADE to re-authorize your ereader.
4. Drag the new book into your e-reader. Select "ereader" (ie: NOT all items, or borrowed items, or...). Try opening the book in the ereader area. If it opens there, it's likely that it will open in your e-reader.
5. Re-upload what were the problem book(s) to your e-reader. Again, select "ereader" in ADE and check that the book(s) can be read there.
6. Disconnect your e-reader from the computer. Be able to read your book(s) at last!

UNFORTUNATELY, it did not work. I can read the books on the ADE app on my PC. BUT the eReader (Kobo Aura) still reports it as not authorized.

SO FRUSTRATING AND ANNOYING!

I know, shouting. But this is not the first time it has happened. Solutions? Real solutions?

Ed