I'm not sure what's causing this issue but maybe try some of the following:
1. Delete your browser's cache/cookies (this seems to be the issue for common mis-redirects on sites I have)
2. Force stop your browser & any extensions that may be keeping it "alive" in the background through Task Manager (so as to completely "shut off" the browser)
3. Uninstall your browser completely & reinstall it.
4. Try a different browser to access the game login. (For me I know Edge works well to keep the login tab open but Chrome seems to have some issues.)
I'd try 1 or 4 before I do any of the others, personally.