(MongoSocketOpenException): Exception opening socket | Unknown host: wisdb1 - database

Question

I tried to connect MongoDb replica-set (3 nodes) with docker.
This is my docker-compose file, i renamed all services from e.g. "mongo1" to "mongoa1" because i have a second app with the same config file:
version: "3.8"
services:
mongoa1:
image: mongo:4
container_name: mongoa1
command: ["--replSet", "my-replica-set", "--bind_ip_all", "--port", "30001"]
volumes:
- ./data/mongoa-1:/data/db
ports:
- 30001:30001
healthcheck:
test: test $$(echo "rs.initiate({_id:'my-replica-set',members:[{_id:0,host:\"mongoa1:30001\"},{_id:1,host:\"mongoa2:30002\"},{_id:2,host:\"mongoa3:30003\"}]}).ok || rs.status().ok" | mongo --port 30001 --quiet) -eq 1
interval: 10s
start_period: 30s
mongoa2:
image: mongo:4
container_name: mongoa2
command: ["--replSet", "my-replica-set", "--bind_ip_all", "--port", "30002"]
volumes:
- ./data/mongoa-2:/data/db
ports:
- 30002:30002
mongoa3:
image: mongo:4
container_name: mongoa3
command: ["--replSet", "my-replica-set", "--bind_ip_all", "--port", "30003"]
volumes:
- ./data/mongoa-3:/data/db
ports:
- 30003:30003
Container are running.
❯ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
fb1fcab13804 mongo:4 "docker-entrypoint.s…" 3 minutes ago Up 3 minutes 27017/tcp, 0.0.0.0:30003->30003/tcp mongoa3
72f8cfe217a5 mongo:4 "docker-entrypoint.s…" 3 minutes ago Up 3 minutes (healthy) 27017/tcp, 0.0.0.0:30001->30001/tcp mongoa1
2a61246f5d17 mongo:4 "docker-entrypoint.s…" 3 minutes ago Up 3 minutes 27017/tcp, 0.0.0.0:30002->30002/tcp mongoa2
I want to open Studio T3 but i get the following error:
Db path: mongodb://mongoa1:30001,mongoa2:30002,mongoa3:30003/app?replicaSet=my-replica-set
Connection failed.
SERVER [mongoa1:30001] (Type: UNKNOWN)
|_/ Connection error (MongoSocketOpenException): Exception opening socket
|____/ Unknown host: mongoa1
SERVER [mongoa2:30002] (Type: UNKNOWN)
|_/ Connection error (MongoSocketOpenException): Exception opening socket
|____/ Unknown host: mongoa2
SERVER [mongoa3:30003] (Type: UNKNOWN)
|_/ Connection error (MongoSocketOpenException): Exception opening socket
|____/ Unknown host: mongoa3
Details:
Timed out after 30000 ms while waiting for a server that matches com.mongodb.client.internal.MongoClientDelegate$1#4d84ad57. Client view of cluster state is {type=REPLICA_SET, servers=[{address=mongoa1:30001, type=UNKNOWN, state=CONNECTING, exception={com.mongodb.MongoSocketOpenException: Exception opening socket}, caused by {java.net.UnknownHostException: mongoa1}}, {address=mongoa2:30002, type=UNKNOWN, state=CONNECTING, exception={com.mongodb.MongoSocketOpenException: Exception opening socket}, caused by {java.net.UnknownHostException: mongoa2}}, {address=mongoa3:30003, type=UNKNOWN, state=CONNECTING, exception={com.mongodb.MongoSocketOpenException: Exception opening socket}, caused by {java.net.UnknownHostException: mongoa3}}]
I don't understand what's wrong. When i rename back to "mongoa1" to "mongo1" it works. But i always have to delete the other docker app and i don't want. Whats wrong in my config?