Continuous network interruptions jitsi meet

I am from germany and a new jitsi meet user. We want to use Jitsi meet only in our own network without any access from “outside”. (internet)
I installed jitsi meet on a fresh ubuntu 18.04 system and everything went fine. Because of the fact that we want to use it only “inside” i did not install a Lets Encrypt ssl certificate. (the name of the server ist video.domain.local)
I can open the website of our Jitsi meet installation and access a room…but after a few seconds i get continuously disconnected an jitsi wants to reconnect.???
Another (little) problem is that i can not disable the mic or camera.
I hope somebody can help me.
Thank you.
Greetings from germany

Are users from the outside able to access your install using the hostname “video.domain.local” ?

The FQDN they use must match the SSL cert you’re using. If the cert is self-signed, clients will need to approve the cert in their browsers.

Are you using port 443?

If not you might need to set up a reverse proxy or change the “bosh:” entry with “http-bind” to have your custom SSL port in your meet config.js

bosh: ‘//FQDN:4443/http-bind’,