Prior to having trouble I was using an older version of Comodo Firewall that had a GUI similar to the one in this post: https://airvpn.org/topic/3405-windows-comodo-prevent-leaks/ (sorry I don't recall the exact version). The firewall was working fine and prevented any form of leaks when AirVPN was disconnected for whatever reason. Upon doing a clean install of Comodo Firewall two days ago and reconfiguring the global rules as described in the tutorial above traffic coming from my computer when the VPN connections is down is no longer blocked based on ipleak.net. Im assuming there is something that changed in the new version of Comodo Firewall because I followed the same procedure as I had in the past.
This blog post: https://www.bestvpn.com/blog/10218/build-your-own-vpn-kill-switch-in-windows-comodo/ also mentioned problems regarding their implementation of preventing leaks upon using the new version of Comodo Firewall, so I don't believe I am following the tutorial provided by AirVPN incorrectly. If anyone else could test AirVPNs initial tutorial with the newest version of Comodo Firewall it would be appreciated just so I know it's not me that is doing something wrong. If that is the case I can take screenshots of what I've done to try to fix my issue.
As of now I have been using the Network Lock feature in the GUI and it seems to be working fine which I will stick to if I can't get Comodo to work. Thanks.