Two Erros Regarding Log In

I’m using the premium version of this plugin and I’m encountering two errors regarding log in…

1.) The login form on the home screen does not work. It is not accepting the password for the account. I must go to /wp-login or /wp-admin in order to log in.

2.) In the settings I have “user permissions” set to “Administrator” only. I was thinking this would mean only admins would be able to log in. However, when I navigate to /wp-login, a user from any role is able to log in.

https://www.ads-software.com/plugins/site-is-offline-plugin/