We have several staff members that can't see a specific assigned tile/link. The tile has many group assignments the user is a member of, but when I view User Access and look at the assigned Link Sources, the tile/link is not listed.
Most likely that is an issue with what we call back-links. When you assign a link to a user/group/OU, the link object will list the assigned user/group/OU. The User/group/OU will then show the assigned link on their object. Sometimes when saving the assignment, AD doesn't set the assignment on the other object.
When a user logs in, the link assignments are read from their OUs, Groups, and individual assignments. So, if the link shows it is assigned to a user/group/OU, but when you look at the user/group/OU and the link doesn't show as assigned, the associated user will not see the link.
Solution
To check if this is the issue, look at all of the user/group/OU objects that show on the link object as being assigned.
If one of those objects does not show the link assigned (on the Assignments tab), go back to the link. Delete that user/group/OU from the Assigned To field and save the link. Then add the user/group/OU assignment back and save the link again. Check the user/group/OU to see that the link now properly shows under the Assignments tab.
The user should now see the link the next time they log into UW.