How to connect to localhost in Docker in Windows Server 2016

Background:

• Am using Windows Server 2016
• Have installed Containers
• Have installed Docker (not Docker Desktop / Docker for Windows): https://docs.docker.com/install/windows/docker-ee/
• Have multiple containers running on the same server
• I need container A to be able to connect to container B (on the same server)

What works:

• Hard coding the public IP address, container A can call via HTTP container B

What doesn't work

• Container A tries to use localhost to call over HTTP to container B
• Have also tried host.docker.internal which absolutely does not work.

What is the best way to do this? I cannot hard code the IP address because the IP address of this server is dynamic on restart, hence why I would like to use something close to localhost.

Any help with this is greatly appreciated.