Unable to create working firewall allow rule

I am running the latest version of avast internet security.
I have a piece of server software running on a machine, and I have an application on that same machine that connects to the server using the localhost address.
I would like to block all external connections to the server software, but still allow access on the machine through localhost.
I have created a block rule that blocks all protocols with in/out direction.
I have tried creating an allow rule with the addresses localhost, 127.0.0.1, and the machines ip, but none of them are working.
Here is a line from the firewall log showing the blocked request:

5/30/2018 9:23:50 PM 0 :: 1688 TCP In C:\Programing\Test\Server.exe Default Rule

I noticed that the Remote address shows up as blank, and I think that might be why I am unable to create a working allow rule.
Any help would be greatly appreciated. Trying to get avast’s firewall to work is getting extremely frustrating!

https://support.avast.com/article/25/ (Firewall FAQ)

I have tried everything in that FAQ. I have also searched this forum/the web for several hours trying to find an answer.

Is there any way to filter requests coming from the local machine?

Contact support: https://support.avast.com/contact