Support

Problem trying to access Joomla admin from one location.
Another location is apparently OK.
IP whitelist setup correctly.
Nothing in log or auto IP list.
No warning emails.

Cannot access Joomla admin pages.
No email messages received.
Change name of plugins/system/admintools directory (to disable it).
Can then access Joomla admin pages and login.
Restore name of plugins/system/admintools directory (to enable it).
In Joomla plugins disable System - Admin Tools
Get admin login notification email
Goto Components / Admin Tools everything looks OK
In Joomla plugins disable System - Admin Tools
Goto Components / Admin Tools everything looks OK
IP of client in admin whitelist

Logout and taken to site front-end
No email messages
Try to go to admin pages, return to front-end
No email messages

Try to use rescue feature - get 401 error page.

Are you using the GeoIP block? That block would not leave a trace in the log.

What exactly happens when they try to log in? Do they get an error or are they redirected to home?

geoip not installed.

Cannot get to login page.

https://thsite.com/administrator
Takes you to
https://thsite.com

I thought GeoIP was a long shot, but it was appealing because it doesn't show up in the log.

Usually a redirect to home is caused by the Secret URL Parameter. See Configure WAF, on the first tab. If you don't include the parameter in the URL, you get redirected to home. But if the IP is in the Whitelist, that disables most of the protections. The pieces don't quite add up here.

Please check the Secret URL Parameter and please double check that the IP really is in the Whitelist. Is the IP static or dynamic?