This question already has an answer here:
When I am logged in to one SE site, then type the url for another derivative SE site in a new tab, I'm already logged in there as usual.
However, when I type
stackexchange.com I see the page not logged in.
Curiously though, if I click Log In, I get what looks like the Sign Up page.
And if I click Sign Up, I get a white page with a long url as text:
THe page's url is
https://stackexchange.com/users/signup?ssrc=head&returnurl=https%3a%2f%2fstackexchange.com and the text shown on the page (I've truncated it in case there might be some security reveal in the code:
https://openid.stackexchange.com/affiliate/form?affId=11&background=transparent&callback=https%3a%2f%2fstackexchange.com%2fusers%2fauthenticate&color=black&nonce=%2brsQWgAAAADlmwDRpG5zEQ%3d%3d&openid.sreg.requested=email&signupByDefault=true&onLoad=loaded&authCode=u%2bdDP1cFtRe5N13hdCOFt6EOZK2w5371%2bLZFRpDf0jtqjwV24gUVxhe%2fE1OUr52WthdUSh3FCX one hundred characters deleted
Screen shot of what looks like a sign up page that appears when I click Log In:
Screen shot of white page with url text that appears when I click Sign Up (truncated):