It doesn't look like the "log in anonymously" option is still even available at log in, and I haven't seen it there for quite a while.
I think I was logged in anonymously when I upgraded to the version that did away with it. Now every time I log in I'm logged in anonymously and I can't figure out how to get around it XD

It’s an account setting now, not a session thing anymore. 

https://invisioncommunity.com/settings/account-security/

Thank you!