Support

You have already answered your own question by telling us that you are being blocked because of "Admin Query String". That's because you need to use the secret URL parameter you have specified in the configuration.

For the meaning of the blocking reasons please consult https://www.akeebabackup.com/documentation/admin-tools/waf-log.html#waf-log-reasons

For the feature that blocks you please see https://www.akeebabackup.com/documentation/admin-tools/web-application-firewall.html#waf-configure under "Administrator secret URL parameter":

Normally, you can access your site's administrator area using a URL similar to http://www.example.com/administrator. Potential hackers already know that and will try to access your site's administrator area the same way. From that point they can try to brute force their way in (guess your username and password) or simply use the fact that an administrator area exists to deduce that your site is running Joomla! and attack it. By entering a word here, you are required to include it as a URL parameter in order to access your administrator area. For instance, if you enter the word test here you will only be able to access your site's administrator area with a URL similar to http://www.example.com/administrator?test . All other attempts to access the administrator area will be redirected to the site's home page. If you do not wish to use this feature, leave this field blank.

Please note that this is the first option you set up in the Quick Setup Wizard page.Please do read the information on the Quick Setup Wizard page carefully! If you gloss over the setup you will get confusingly get locked out of your site since Admin Tools will do what you configured it to do, not what you thought you configured it to do (speaking from experience; I've done that myself a few times I was in a rush and got a bit more sloppy than I should).

You're welcome and thank you for your kind words :)