JVB & Turnserver not working

Hello together,

I have a problem with my Setup. I installed and configured the turnserver. I used this guide:

The problem is, that we can not see each other in a room. I see the following error in the jvb.log:
java.lang.Exception: Address discovery through STUN failed

The turnserver is one the same machine and listens on port 5349. Here is my turnserver.conf:
#listening-port=3478
tls-listening-port=5349
listening-ip=XXX.XXX.XXX.XXX
relay-ip=XXX.XXX.XXX.XXX
#external-ip=XXX.XXX.XXX.XXX/XXX.XXX.XXX.XXX
fingerprint
use-auth-secret
static-auth-secret=super-secret
realm=super.secret.com
total-quota=100
bps-capacity=0
#no-udp
#no-tcp
stale-nonce=600
cert=/opt/fullchain3.pem
pkey=/opt/privkey3.pem
cipher-list=“ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256”
ec-curve-name=secp384r1
dh-file=/etc/ssl/certs/dhparam.pem
no-stdout-log
log-file=/var/log/turnserver.log
simple-log
no-multicast-peers
cli-port=5766
no-tlsv1
no-tlsv1_1

I added the following in the JVB sip-communicator.properties:
org.ice4j.ice.harvest.STUN_MAPPING_HARVESTER_ADDRESSES=super.secret:443

And this in my prosody-config:
external_service_secret = “super-secret”;
external_services = {
{ type = “stun”, host = “super.secret”, port = 443 },
{ type = “turn”, host = “super.secret”, port = 443, transport = “udp”, secret = true, ttl = 86400, algorithm = “turn” },
{ type = “turns”, host = “super.secret”, port = 443, transport = “tcp”, secret = true, ttl = 86400, algorithm = “turn” }
};

Did I do something wrong or is something missing?

Kind regards
Justin

Don’t change this line. JVB cannot find its public IP address using internal STUN service