Top-level autologin does not fully work for newly created temporary accounts, even when it works for a normal account on the same browser.

Steps to reproduce:

• Edit a page without logging in on test.wikipedia.org (in a browser that blocks edge login and subrequest autologin but not top-level autologin, such as Chrome in incognito mode)
• Navigate to en.wikiversity.org
• Click Login
• Instead of getting logged in, you end up on the login page. However, if you press the browser's back button, you are logged in.

The top-level autologin sequence looks normal; it ends in the /setCookies step with X-Centralauth-Status: success, and all the session cookies are set correctly. Special:CentralAutoLogin then redirects back to Special:UserLogin, which deletes the CentralAuthAnonTopLevel cookie (as it would on success), but then redirects to the central login domain.