nbstripout installation causes incorrect 'git status' results

I seem to see changes for notebooks I haven't touched since I installed nbstripout. Interestingly, when I uninstall nbstripout and install it again, the changes are gone. Besides general performance issue, this prevents us from adopting nbstripout as a team.

 $ git status
On branch master
Your branch is up-to-date with 'origin/master'.
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)
... list of notebooks I haven't touched ...

----(after uninstall nbstripout and install it again)---

 $ git status
On branch master
Your branch is up-to-date with 'origin/master'.
nothing to commit, working tree clean