404 Error On Published Page

I recently noticed that one of our published pages, which has been working without issue for some time, recently started returning a 404 error on our site.

SITE: https://www.event1software.com
PAGE: https://www.event1software.com/services/kb/product-documentation/integrator/menu-reference/file-menu/logon/Trimble-prolog-manager/

I changed from custom permalinks to normal and even the Page ID returns the same thing. No changes were made to the page content.

Anyone have thoughts on why that might occur? Any assistance is greatly appreciated.

Thanks!