Unique Permissions for Library Folder not working: SP Hybrid

Hello - I am a Site Administrator for an intranet site in which we have a central repository library for assets (links, pdfs, etc.).  The entire site is open to our Domain users to view.  The central repository library has 2900 items.  I have a request to create a folder in this library with unique permissions limiting access to only those chosen few.  I have created said folder, disinherited said folder, limited access to said few yet "everyone" can still access.

As a workaround, I went to the dept subsite and created a document library and posted 2 files.  I have disinherited said library, revised the permissions, limited access to said few yet "everyone" can still access.

Attached is a screenshot of general user permissions. 

Do I need to meeting with the SharePoint Central Administrator to change these settings? or is there something at my level I can do to make the restricted access actually work? Thanks!!