IIRC technically this chapter isn't part of the monthly series, as it was only included in the volume release of the manga. It's still a very odd chapter though as I think it's the only instance in JoJo where one of the chapters was only in the volume version (except for the bonus chapters from earlier in this part which are outside of the main set of chapters, and the one instance in Part 5 where a chapter was split in two for the volume version).