Good think I've kept my Recovery code because I need to use it every time to log into the forum (updating with each time, of course). I have the Google Authenticator app installed on my phone but when I enter the number (before it times out, of course) this forum says it's an invalid code. I do notice that in Authenticator it shows my old forum email, not my current Gmail one. If that's the issue, how do I change that? I don't remember how Google Authenticator even knows about this forum.
Google Authenticator doesn't know nether about the forum, nor about email. All what it needs - the unical personal code, generated by the forum. The code doesn't contain any information like your email and login.
When you stored the code in Authenticator, you appended a label to it( because the Authenticator can contains a several codes for different resurses). You can use any string as a label, including an email.
I suppose, that it were you, who set a email as a label. And because it is an old email, it means that it for your old login.
Thanks. But I still don’t know why the code doesn’t work, presuming the date/time on my iPhone and the forum server are in sync. Can I opt out of 2FA?