Apostrophe in title not displayed correct

On the main/overview page titles which include an apostrophe are displayed correct, e.g.

You're my Dinner!
https://www.fakku.net/viewmanga.php?id=3213

But on the related manga and view online pages it is displayed incorrect, e.g.

You\'re my Dinner!
https://www.fakku.net/viewmanga.php?id=3213&mode=related
https://www.fakku.net/viewonline.php?id=3213

Most other mangas with an apostrophe in the title behave the same.
The apostrophe seems to be double escaped or something like this...

PS: If you are not logged in the top bar reads "Login About Join About Contact".
Why is there About twice?

I don't think it matters which browser is used.

If you are logged in, it's fine - one about link:


But if you're not logged in, there is one on the left side and one on the right side and I just wondered why: