It is but not kinda, i check all the volumes to confirm before saying what i said though, and all of them since Volume 2 are mostly misnumbered due to volumes and magazines (like
Volume 2, Chapter 8 is Chapter 12 in here), and that
extra chapter from
volume 3 that got labeled as 16 here in mangadex didn't help either, so this offset problem actually come from here (well magazine chapters didn't include a number or title either, this was only in volumes, as you can see in early chapters that used magazine and those done by EvRi-Zero)
There is no repeated number in the Volumes, not in Volume 5 either (
ToC for titles),
Chapter 27 in Volume 5 is 28 in mangadex (27 is under V4 in MD too lol),
chapter 28 is 29 in mangadex,
chapter 29 is 30 in mangadex,
chapter 30 is 31 in mangadex,
chapter 31 is 32 in mangadex and
chapter 32 is 33 in mangadex, and so on, Cyan Steam most likely started editing out the titles when changed from magazine to volume raws at 20 (19 in v3) trying to cover up, instead of well fixing numbers (super noticeable they edited numbers in
20 and
21), but ended a mess, because like i mentioned before, the offset was because the extra that was labeled as 16, because then
Volume 3, Chapter 16 ended labeled as chapter 17 in mangadex and it started to offset the rest of them that we got to this point
