Local Install on Debian server

Hi all
I have installed Jitsi meet on my own server to be used locally.
Some time ago, I did the same with success but I cannot find the docs on this site anymore and cannot remember what I did.

I installed in a LXC container, Jitsi runs and I can access the webUI but get disconnected every 30 seconds.
Searching here and on the net did not give me a solution.

Can anyone point me in the right direction please?

Thanks a lot in advance!
Nick

HARVESTER lines on /etc/jitsi/videobridge/sip-communicator.properties?

org.ice4j.ice.harvest.NAT_HARVESTER_LOCAL_ADDRESS=$LOCAL_IP
org.ice4j.ice.harvest.NAT_HARVESTER_PUBLIC_ADDRESS=$EXTERNAL_IP