Introducing a new container to a docker environment interferes with other containers - docker

Question

I’ve spent an awful long time trying to debug this. I have an already populated docker compose file with multiple containers running, all on the same network. The containers consist of a tomcat9 server(Server A), a hazelcast container, and a hazelcast-mancenter container, and then an apache server.
I want to introduce an additional container, which is a tomcat7 server(Server B), and for some reason it interferes with the original tomcat server(Server A). Server A never gets to a start up state when server B's container is running.
Whenever Server B is off, Server A works no problem(after a restart). The moment Server B comes on, Server A poops out.
For some reason Server B also attempts to connect to Hazelcast or affects it. Even if I take Server B off the network as the other containers, there is still interference. I am certain that Server B is not attempting to connect to the original Hazelcast container.
What is going on? Shouldn’t the container be isolated?
docker-compose.yml
version: '3.7'
services:
server_a_tomcat:
container_name: server_a_tomcat
image: server_a:latest
ports:
- "8080:8080"
- "5005:5005"
networks:
- network_a
depends_on:
- server_a_mountebank_local
volumes:
- …/java-config
- …/server_a_tomcat.war
- data-volume:/usr/local/ssl
environment:
- …
server_a_mountebank_local:
container_name: server_a_mountebank_local
image: mountebank:latest
volumes:
- …
networks:
- network_a
ports:
- "8083:8083"
apache_local:
container_name: apache_local
image: apache_local:latest
ports:
- "80:80"
- "8055:8055"
depends_on:
- server_a_local
volumes:
- …/httpd.conf
- …/extra-httpd.conf
- …
- data-volume:/usr/local/ssl
networks:
- network_a
stdin_open: true
tty: true
hazelcast_local:
container_name: hazelcast_local
image: hazelcast_local:latest
ports:
- 11415:5701
depends_on:
- mancenter_local
mancenter_local:
container_name: mancenter_local
image: mancenter_local:latest
environment:
- HAZELCAST_IP={{ container_private_ip }}
- JAVA_OPTS=-Dhazelcast.mc.rest.enabled=true
ports:
- 8100:8080
networks:
- network_a
server_b_tomcat:
container_name: server_b_tomcat
build:
context: '.'
dockerfile: 'Dockerfile-server_b_tomcat’
ports:
- "9090:8080"
- "5015:5005"
environment:
- ...
networks:
- network_b
depends_on:
- redis
redis:
container_name: redis
image: redis:5.0.5
ports:
- "6379:6379"
networks:
- network_b
networks:
network_b:
driver: bridge
name: network_b
network_a:
driver: bridge
name: network_a
volumes:
data-volume: