It looks like some of the other "chapters" have been uploaded separately though.
Chapter 3: https://mangadex.org/title/80956559-05cd-46f9-abab-ed306f753f40/model-ni-scout-sareta-otokonoko
Chapter 6...
Onimai currently looks like this in my feed:
Ch. 75 - Latest
Ch. 74
Ch. 74.99
Ch. 74.1
Ch. 62.1
But if you navigate though the chapters starting at chapter 74 the order is:
Ch. 74
Ch. 74.1
Ch. 74.99
Ch. 75 - Latest
It looks like it's a link now for chapters that have a thread, though still a button otherwise.
Also I noticed a new thread that said it had 0 comments, but actually it had 2. I guess the comment count is cached for a bit?
The forum link for a chapter appears to be handled using JavaScript instead of an actual link, so you can't middle- or right-click on it. It also doesn't get a shaded background when you hover over it like the other links within a chapter link.
oof. Having the main character end up in lewd situations with their teacher is one thing (since that what this entire manga is about), but stripping the entire class is getting dangerously close to hentai levels.