Chapter 35

I think it's not about the translation itself, i think it's about the timing of uploading the chapters? People won't buy from the official site if it's being uploaded here waaaaaaay before being uploaded on Lezhin so it's harming the author's income that's why the chapters got taken down

Yeah, I think this was it. I remember reading the fan translations and a lot of people in the comment section were mentioning that the fan translations should be taken down because we're already receiving the original translations. The fan translations would only lead to people not buying the chapters on Lezhin (since the fan translations would have been uploaded before the original translations) and ensure that the author misses on much deserved support.

As far as I remember Blood Bank doesn't have any fantranslations uploaded here, those are all official ones. KS had a few fan translated chapters (some of them were really horrible on top of that) but it had nothing to do with not wanting to upload official translations (if there are fantranslations made during season 3 then I'm not aware of them since I dropped it about 10 chapters into season 3). Those (the bad ones) were made during season 1 when it wasn't released simultaneously and people just wanted to be ahead of the official release.
They (and other Lzhin titles) were taken down because mangago feared they would get into trouble for having those titles. Most (if not all of them) returned after some time but they simply uploaded the chapters that were already there before they got taken down.
As Xiaoma said, it's mostly about uploading chapters before the official release. That's what's troublesome. If the fantranslations came out weeks after the official ones it probably wouldn't be much of a problem.
Also you're not allowed to spell out Lzhin correctly, it might get your post deleted.

Ahhh, alright that makes sense, thanks!