How do you remove a project from Launcher Library without deleting, renaming, or moving the project?

This question has been asked before on multiple occasions. Everything points to the following post:

Tmek provided an answer that has worked in the past. The problem is after removing the RecentlyOpenedProjectFiles= “whatever project path” the launcher still displays the projects even after complete system restarts.

The only difference we can come up with is that we have switch to new machines that had brand new downloads of all the unreal versions. (Some clients use older versions) As we don’t have access to older downloads we cant verify that this may be a factor but at this point we are grasping at straws.

It is important that these files don’t move or change names. We simply want to clean up our ever growing list of library projects.

Any help in the matter would be greatly appreciated.