Trying to read any of the first 9 Chapters of Tomo-chan is a girl will treat it as if it's on ch 912

[ichigoteguz]

Saw some other users mention it in the comments so I went to check it out, effectively, once you go into any of the chapters from 1 to 9, the side panel will say 912, and if you try to go to the next chapter it will take you to the title page, don't know if any other long manga are behaving the same.
https://mangadex.org/title/15722/tomo-chan-wa-onna-no-ko/chapters/10/

 

[BzzBzz]

https://mangadex.org/thread/67682