I have PDF thumbnails duplicates on Windows 8

Good day to all:

In my PC, I can't identify the origin of the mistake.

In the PDF thumbnails, Windows (8), it shows me the thumbnails (large icons or very large icons, it's the same), but for two different PDF's (files), the system shows the same thumbnail.

For years I've used Adobe Reader, and this problem is the same for many years.

Do you have any solution for this issue?

Thanks in advance.

Kind regards.