Steps to Reproduce: Run Firefox 66.0.5 on macOS 10.13.6. Open an article on German Wikipedia with Visual Editor and (1) select a footnote, or (2) select some phrase of text and try to move it by drag and drop.
Actual Results: The footnote won't move, while the phrase will move.
Expected Results: In both cases you would expect to be able to drag and drop these elements of text. AFAIR it was possible to move footnotes like this until recently.
Sorry if this should have been reported before, I didn't find any bug that fits in here.