Nostalrius Begins - Quality wow vanilla realm (1.12)

Hello I've been having the problem about disconnecting before anything else because I hit the recommended realm not seeing it was the test realm. Now whenever I try logging in to ANY account I get disconnected no matter what. I've searched around the forums for help but everything I've tried doesnt work. Keep in mind I've reinstalled WoW 1.12 from various sources and always deleted everything I could find from the previous but no matter what client it always disconnects me on any account. Could someone tell me something new other than setting the realmname and deleting folders WDB and WTF. Or and admin look at my problem please. Thank you.

PS My account will log into other computers, just not my main.

Edit: I've spoofed my mac address and ip address, tried on another computer on the same network and across the country, the same network doesnt work. Can someone give me some help pls?

Edit2: I can connect to TheRebirth just fine but when I switch back I get auto disconnected

Here's a list of things I've done with Handtooch trying to get him online:
Port Forwarding listed ports TCP, 8000-8100 and 3724. Then turned off automatic port forwarding. Tried both ways.
VPN.
Changing IP.
Restarted Home connection.
New Client DL
Deleting WTF, WDB, INTERFACE
Both tried realmlists.
Connected fine to rebirth.
Turned off AntiVirus/Firewall.
Tried different machine.
Tried phone internet.
System reboot.
Disable/enable network adapter.
Made another account.
Tried said account on my computer (worked)

There seems to be lots of funky issues because of their warden anti-cheat implementation.

I had the 1.12.2 enGB client. which did the same shenanigans to me.

It must be exactly a version 1.12.1 client not modified in the data folder.

viewtopic.php?f=32&t=638
I torrented the client from this page, unzipped it to a new directory and changed the realmlist.wtf and then everything has worked for me since.

I sometime get some problems with login, but I just keep retrying and it will let me in in a few times. I guess the server is on full load

It is easy to see if you are trying to log in to the wrong realm: https://mrkr.io/2c5eIQj4El
It should say something with Test there instead of Nostalrius begins. If there is not realm listed there, you have a clean WoWFolder/WTF/Config.wtf file. Otherwise it's >>SET realmName "Nostalrius Begins"<< in that file. But as you say you have tried a clean install, so it should not be that.

Other than that I have no good suggestions. You say that you can log in from other computers. Is it possible to zip that installation and try it on your computer?