I'm comparing dev branch in my fork with the dev branch in the upstream. It shows diff of 30 commits, but 0 files changes. All the commits appear in the diff are old commits which already merged to the upstream (mainly type of "Merge branch dev.."). This makes an issue where each PR shows those many old commits. Tried rebase and still showing the same diff.
Why this happens? Can you please assist how to resolve? We're using Github for Enterprise so can't attach a url that show the diffs.