Thanks for the quick reply Paul.
I copied the 2017 directory from my DESKTOP computer and saved it on a USB memory stick. I then opened my Windows 10 LAPTOP, running Office 2007, and I am able to view the Author list in FILE EXPLORER, as normally as I have always done. No problem.
I already tried all the various Office repair programs, and made sure I had all the latest updates. That is why I originally thought one of the latest Microsoft updates killed my ability to view the list of Authors when I used FILE EXPLORER.
As I said; if I save the documents in the newer format (.docx) everything populates and lists correctly. Its only (my last 10 years) my older documents, saved in the ".doc" format that no longer populate the "AUTHOR" column in File Explorer.
I know; Its a strange a ridiculous problem. And it only happens on my DESKTOP.
I'll probably waste a rainy weekend and open/save as/ change all these 2017 ".doc" files over to "docx" files, one at a time. Frustrating!