Angular 5 image not communicating with node.js image in swarm ...!

I have the following docker(Server Version: 17.12.1-ce , API version: 1.35 ) swarm setup:-
Virtual Machine 1 - Angular container 1
Virtual Machine 2 - Angular container 2
Virtual Machine 3 - node.js container 1
Virtual Machine 4 - node.js container 2
All the containers are connected to user defined overlay network.
I am able to ping node.js container 1 from inside of angular container 1
and vice versa.

Problem:-
My angular application has to make api calls to node and the url containing ip address details are mentioned in environment.ts file(custom angular configuration file). i see that ip address /host name/ node service name is not getting recognized due to which communication between angular & node containers is not happening.
i see request timeout error showing up in logs. Can some one help me in knowing what could be going wrong ?