You should be able to go into the prefs.xml file located in your Crushftp9 folder located in your Appdata (if you use the standard locations) share. Open the XML file and the banned ip's should be listed. Below is an example of a banned IP. Look for your ip or the ip of your reverse proxy server and delete that block.
<ip_restrictions_subitem type="properties">
<start_ip>61.75.30.52</start_ip>
<type>D</type>
<stop_ip>61.75.30.52</stop_ip>
<reason>05/29/2019 02:43:48.047:password attempts</reason>
After you have deleted the banned ip you can search for the "never_ban" and add your lan range.
<never_ban>127.0.0.1,10.0.*,172.*</never_ban>
Then save and restart the docker container.