Hi Peter,
We user Shibboleth plugin, and have a decent amount of users. Email address as the username is mapped from the user attributes in SAML Response, and WP allows that without issues. They are listed as normal usernames in the All users list.
The setting was unchecked for “Immediately lock out invalid usernames” when the plugin was activated but started to lock out users while displaying the user’s nicename in logs, for example: “usernamedomain-edu” (email: [email protected]) along with the failed valid username rule message.
Update – Looks like though, it’s not catching it anymore. It could have been temporary during WF activation perhaps? I had to set all rules bypass for our IP, to unlock the user accounts.
Thank you for your response though.
Shweta