If you modify a related object (relation at the attribute level), the system does not update the reverse related object, but old cached content is viewed.

Instead, it's working as expected in objects with relations at the object level.

Steps to reproduce

1) Fresh installation of eZPublish 3.8.6.
2) Create a new class (you can copy the folder class) with an "Object Relation" (or "Object Relations") datatype attribute, and name it "Class Test".
4) Create a file object and name it "xyz" in the Files folder of the Media Library.
5) Create a "Class Test" object in the Content Structure, name it "Test" and relate at the attribute level with "xyz" file (it is important that "xyz" file is not children of the "Test" object).
6) Go to the public site at the object "Test" page; you can view the name of the file "xyz".
7) Now, modify the name of the "xyz" file to "abc".
8) Return to the public site and refresh the "Test" page: you can view the name of the file is still "xyz" and not "abc".