Hi @wadham
The option to “Prevent the use of passwords leaked in data breaches” was first introduced in “7.1.0” then it was enhanced in “7.1.1” to allow a login if the user has previously logged in from the same IP successfully and displays an admin notice suggesting changing the password. And this behavior wasn’t modified in “7.1.2”.
I’m a little bit confused regarding which version you were on and which version you were trying to update to?
By following procedures in “Forcefully regain access to your site” on that guide, you should regain access to your website again and you can disable this option if you want.
@catwingz Still your password might be in one of the breaches out there although you are an admin and trying to log in with the correct password. You can read more about this feature in this blog post.
To get the email with instructions to regain access to your website, the email you enter in the form must be the same email used while registering the admin account on you website, also make sure to check spam emails folder and double check that your web server can send emails successfully.
Thanks.