Only one container not connecting or losing docker network connection

@meddream
@jodogne

Dear all,

I have a bit of a weird (at least to me) problem. I would like to run meddream/orthanc-dicom-viewer for further implementation into a hospital management system. The instructions are quite straight forward:

# 1
docker network create orthanc

#2
docker run --rm --entrypoint=cat jodogne/orthanc-python /etc/orthanc/orthanc.json > ./orthanc.json

#3
curl -o meddream.py www.softneta.com/files/meddreampacs/lite/meddream.py

#4
sed -i '/orthanc\/plugins\"/{n;N;d}' orthanc.json && sed -i '/orthanc\/plugins\"/a ],\n"PythonScript" : "/etc/orthanc/meddream.py",' orthanc.json  

#5
docker run --restart=always --network=orthanc --name orthanc -itd -p 4242:4242 -p 8042:8042 -v ${PWD}/meddream.py:/etc/orthanc/meddream.py -v ${PWD}/orthanc.json:/etc/orthanc/orthanc.json -v ${PWD}/orthanc-db/:/var/lib/orthanc/db/ jodogne/orthanc-python

#6
docker run --restart=always --network=orthanc --name meddream -itd -p 80:8080 -e integration=study meddream/orthanc-dicom-viewer:7.9.0

# 7 --> Transferring test data:
docker run --rm --network=orthanc meddream/dicom-studies:latest storescu -cSENDTOPACS@orthanc:4242 .

The problem I experience is that whenever I run command 5, the container orthanc is not connecting to the network orthanc. However, command 7 connects without any problems the container meddream to the network orthanc. A docker network inspect orthanc results in

[
    {
        "Name": "orthanc",
        "Id": "4d16f08dbe80b8b8bc1735064ee476218572853e114817533fc329040b32c133",
        "Created": "2022-06-01T13:06:07.201132504Z",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": {},
            "Config": [
                {
                    "Subnet": "172.23.0.0/16",
                    "Gateway": "172.23.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "75579d900bffb9cc756e50e7fed422b1b8e733f836558de0abf03596ed2e8cea": {
                "Name": "meddream",
                "EndpointID": "ce7a58e7e2f9cdf426cf301e340e7838d147b0b3d6a2588325b38e76966122fa",
                "MacAddress": "02:42:ac:17:00:02",
                "IPv4Address": "172.23.0.2/16",
                "IPv6Address": ""
            }
        },
        "Options": {},
        "Labels": {}
    }
]

When I run command 5 without the flags -it, the container connects to the network. However, the moment I ran command 6, the orthanc container disappears from the orthanc network and I am left with the network output above. When running command 7 to move test data to the orthanc container, I get

docker run --rm --network=orthanc meddream/dicom-studies:latest storescu -cSENDTOPACS@orthanc:4242 .
Scanning files to send
..........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
Scanned 1,066 files in 0.467s (=0ms/file)
13:31:00,417 INFO  - Initiate connection from 0.0.0.0/0.0.0.0:0 to orthanc:4242
storescu: orthanc: Temporary failure in name resolution
java.net.UnknownHostException: orthanc: Temporary failure in name resolution
        at java.base/java.net.Inet4AddressImpl.lookupAllHostAddr(Native Method)
        at java.base/java.net.InetAddress$PlatformNameService.lookupAllHostAddr(InetAddress.java:929)
        at java.base/java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1515)
        at java.base/java.net.InetAddress$NameServiceAddresses.get(InetAddress.java:848)
        at java.base/java.net.InetAddress.getAllByName0(InetAddress.java:1505)
        at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1364)
        at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1298)
        at java.base/java.net.InetAddress.getByName(InetAddress.java:1248)
        at org.dcm4che3.net.Connection.hostAddr(Connection.java:892)
        at org.dcm4che3.net.Connection.getEndPoint(Connection.java:932)
        at org.dcm4che3.net.Connection.connect(Connection.java:1047)
        at org.dcm4che3.net.ApplicationEntity.connect(ApplicationEntity.java:629)
        at org.dcm4che3.net.ApplicationEntity.connect(ApplicationEntity.java:649)
        at org.dcm4che3.tool.storescu.StoreSCU.open(StoreSCU.java:517)
        at org.dcm4che3.tool.storescu.StoreSCU.main(StoreSCU.java:289)

which is not surprising given the containers are not on the same network. I am running docker on a Ubuntu 20.04 LTS, proxmox VM.
I hope you can help me out guys!
Cheers!