sleeplessinDC on "WordPress News box is out of date--how does it update?"

The WordPress News box on the Dashboard's home page for five of my eight websites hasn't been updated since WordPress 4.3 “Billie” 18 Aug 2015. Currently this box has:
WordPress News
WordPress 4.3 “Billie” 18 Aug 2015
Version 4.3 of WordPress, named “Billie” in honor of jazz singer Billie Holiday, is available for download or update in your WordPress dashboard. New features in 4.3 make it even easier to format your content and customize your site. Menus in the Customizer Create your menu, update it, and assign it, all while live-previewing in […]

One of the ones that has been updated to 4.5.3 is on the same server, same host, same domain as the five that haven't been updated.

I'm wondering why it hasn't updated since version 4.3 and if it shows that some updated files in the newer releases haven't been installed?