I've got a weird problem – in about 30% cases I can't remove Italic attribute from text that both Bold and Italic.
For example the summary for http://www.tvmaze.com/shows/8574/the-chase. I'm selecting a title in editor and can remove Bold from it, but not Italic. Clicking [I] button just does nothing. Tried in both Safari 10.0.2 and Chrome 55.0.2883.95 on Mac.