Can't access login page

I just updated iThemes Security today to 4.5.8. Now new users can not access the login page from the link. New users who have not accessed my site in the past get a redirect loop when they try to get to the login page. This happens on all browsers I have tested IE, Chrome & Firefox. It opens fine on computers that have accessed the login page prior to today. Any thoughts or help? I didn’t change anything else on the site besides the update and a few security settings in iThemes. I have changed all the iThemes settings back to see if one of the settings caused this redirect loop, but this did not solve the problem either.
Thank you in advance

https://wordpress.org/plugins/better-wp-security/