Superior document link not updating on the DIR

I am trying to find out if there is a setting in regards to the superior document field that's inside of a DIR. For instance, let's say the parent document is X-12345 and the version number for it is 04. This particular document is a superior document to X-12345-05. If a user does a new version on X-12345, then the superior document field should automatically update since the main document has been revised, yet it never did and still contains the previous version. I'm wondering if there is a setting that might have been turned off by some chance. Any information will be helpful, thanks.

Brian