Custom Log in is triggering “Logged out user” for new user?

If I go to my custom log in URL (I’m in a subdirectory, so in this case it’s example.com/blog/custom-log-in-url) after logging out and in in my normal browser, it works fine. However, if I go incognito or use another browser with which I’ve never been logged in, it performs the action for “When a logged out user attempts to access the old login page”, (I have it set to redirecting to homepage to test it) making it impossible for a new user to log in.

I’m not entirely sure what the difference is, but all I’m noticing is in my main browser I am able to log in, but sending someone the link it doesn’t work, in addition to the two use cases above.

Thanks very much!

Jake