User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:71.0) Gecko/20100101 Firefox/71.0

Steps to reproduce:

Open the website http://topxnxx.club/
Open a bookmark in the same tab

Actual results:

A website different from the website corresponding to the bookmark opened up

Expected results:

The website corresponding to the bookmark should have opened

NSFW, for anyone else trying to reproduce.

I can confirm this issue, looks like that website intentionally redirects to yet another website with similar content.

I'm not a web developer, but I think I found the correct snippet of code:

window.onbeforeunload = function() {
[...]
setTimeout(function() {
window.open("http://feedhub.club/iyxZ", "_blank");
window.location.href = "http://feedhub.club/iyxZ";
}, 0);
[...]
};

Well, trying to built a mini-example from this it seems to be only part of the trick. I leave that for real developers to debug ...

Proof of concept page (not by myself): https://mozhelp.dynvpn.de

i created a extra page to demonstrate the behavior
https://mozhelp.dynvpn.de/dateien/wl/
In Opera and google Chrome it opens the wanted bookmark when I click on it.