NAS Problem to see other Clients

[deleted]

I have a little problem as it says in the heading. About the history:
I have a Plex server running on my Synology NAS. My daughter has now moved out and so that she can continue to use the Plex server, I have installed an Openvpn server on my small vServer - which I have been renting for a while anyway. I set up the NAS via Control Panel ----> Network -----> Network Interface as Openvpn Client. All other end devices are also set up as clients. The contents of Client.ovpn's are all the same except for the certificates. The DS also connects to the server, but cannot see any client. The other clients can all see each other. Of course, this means that no client can connect to the Plex Server. I hope you can help me further

port 1194
proto udp
dev tun
ca ca.crt
cert xxxx.xxxx.de.crt
key xxxx.xxxx.de.key # This file should be kept secret
dh dh.pem
client-config-dir /etc/openvpn/clientconfig
push "topology subnet"
topology subnet
server 10.8.0.0 255.255.255.0
ifconfig-pool-persist ipp.txt
client-to-client
keepalive 10 120
tls-auth ta.key 0 # This file is secret
key-direction 0
auth SHA256
cipher AES-128-CBC # AES
comp-lzo
user nobody
group nogroup
persist-key
persist-tun
status openvpn-status.log
verb 3
management 127.0.0.1 5555

client
dev tun
proto udp
remote xxxx.xxxx.de 1194
resolv-retry infinite
nobind
user nobody
group nogroup
persist-key
persist-tun
remote-cert-tls server
comp-lzo
log-append /var/log/openvpn.log
verb 5
cipher AES-128-CBC
auth SHA256
key-direction 1
FROM HERE THE CERTIFICATES ARE INSERTED

The content for the NAS in / etc / openvpn / clientconfig then looks like this:
ifconfig-push 10.8.0.3 255.255.255.0

[deleted]

I think I've narrowed the bug down, but my Linux knowledge is not so good to fix it. The client.ovpn of the NAS is a little bit different than the others. This

group nogroup

I had to change to this

group nobody

Otherwise the NAS got out with the error

failed to find GID for group nogroup
Exiting due to fatal error

Now I assume that since all other clients are in the nogroup group, the NAS is therefore not seen by the other clients and vice versa. Is my guess correct?
Now I'm a little confused, the command

cat /etc/group

on NAS resulted in:

nogroup:x:65534:

so the group does exist, right? Then why does the NAS get out with the error message?

failed to find GID for group nogroup
Exiting due to fatal error

Pippin

Don't know why but Synology NAS uses Apparmor:
https://en.wikipedia.org/wiki/AppArmor