Story changing order on its own in Current

We've seen this for the past two days or so.
1. Put story at the bottom of current. It appears as if it is going to stay there.
2. Later, not quite sure when, the story moves near the top of current on its own.
3. This is happening in our current sprint with the story called "Autofill prepay on receipts page". #189218 Jon put that at the bottom after the Sprint End release marker.
4. The history of the story shows that it should be after the release marker Sprint End which is at the bottom of current. However if you look at current you will see that it is not in that location.

I just moved that story into our icebox so no one will work on it. I added a story called "test story" 189402 and put it in the same place to see if that moves on its own too.