Templates in Word Startup Folder are not loading

Hi!

We have a custom word template that is copied to every users's %appdata%\Microsoft\Word\Startup folder.   There also also vendor provided templates in that folder for a couple of our applications (Worldox, compareDocs)

For some users, the templates in the Startup folder will not load.   All of these templates should add a tab to the ribbon in Word.  There seems to be no pattern regarding OS build or Office build regarding whether the templates load for a particular user or not.  

We have checked and the templates are in the Startup folder and that folder is a trusted location.

For some users, the templates will show up as inactive.  You can make them active, however, the setting does not persist.  After closing Word and reopening, the templates are inactive again.

For other users, the templates do not show up in the list at all (as either active, inactive, or disabled).

For another group of users, everything works as expected.

We also have a Remote Desktop farm, and the templates don't load for one group of users, but load correctly for the rest of the users in the organization. 

Any ideas where else we can look to troubleshoot this issue?