Ubuntu 18.04 GUI File Manager Weirdness

OK, first of all *I* don't use a GUI File Manager. However I provide IT
support for the local library where most people do use the GUI File Manager.
All of the machines are running an up-to-date Ubuntu 18.04. The only other
weirdness is that the /home filesystem is NFS mounted and user authentifcation
is via LDAP.

What is happening is that users cannot open folders on their desktop. Either
left clicking on the folder icon or right-click and Open. Nothing happens.
They can open up their files if they explicitly launch the GUI File Manager
from the launcher (file cabinate icon).

What is going on? Is this part of Gnome3's adversion to starting programs
from the desktop? Or is there some other weirdness going on?