I re-opened and checked again. It turns out that for most of the files listed under "recent" in Word, the modification times do not match the times listed in File Explorer. Out of 9 files I checked, in only one case do the modification times match. (In
case it makes any difference, that is a file that I had saved elsewhere, then copied and pasted it into this folder and continued to work on it.)
Sometimes the modification times listed in the Word recent list are earlier and other times they are later than listed in File Explorer. The time difference can vary from a few hours to days. In one case, the "Date Modified" in File Explorer is 4:32 PM
February 12. The modification date for the same file in the Word Recent list is 9:37 AM March 13.
This is baffling, especially because the differences are so inconsistent. Any further thoughts?