Steps to reproduce:
- Go to https://en.wikipedia.org/w/index.php?title=John_Dewey&oldid=666332549&veaction=edit
- Double-click on the infobox to edit it
- Change any of the fields (e.g. remove the comma under "alma mater")
- Click "apply changes"
Result: The citation which is used within the infobox template, "John Dewey, How we think (1910), p. 9.", suddenly shows up on top of the article text (while still listed under "References" as usual). The article looks fine after saving, though.
Reproduced also in these two examples: