thank you for your answer to my question.
As I mentioned, we use the JitsiMeet software in an educational scenario for “Bug-In-Ear-Coaching”, which means, that one teacher is in the classroom with two IPads with the JitsiMeet-App, and another teacher is in another room, a couple of meters away, live-coaching the classroom-teacher with a laptop, and the JitsiMeet-software in a firefox browser.
For that, I use a laptop with Ubuntu 18.04.3, on which an instance of the JitsiMeet server is running, and also the client for the coach is running on this laptop.
All devices are connected via WiFi to a NAT-Router (TP-Link Archer C9) with static internal IP-Adresses. The Router has no internet connection, because it would legally not be allowed (here in Baden-Württemberg, Germany) to use an internet connection for such purposes.
This scenario worked without problems with an older version of the JitsiMeet-App (unfortunately I don’t know the version number now; I think it could be 19.2.0, but I’m not sure). I had entered the server’s IP-Adress in the settings of the JitsiMeet-App, and the connection was established.
Now I had done an update to the new version of the JitsiMeet-App on the IPads (which is version 19.3.1 now), and when I want to start a call now with the two IPads, the App trys to connect, but finshes this attempt after a couple of seconds with the error message “your connection has been disconnected. Please check your network connection. Connecting again in x seconds” (free translation, because it’s in German).
I only can connect the firefox client for the coach, but unfortunately not the IPads.
Additionally, I have to tell, that I had this problem before, a couple of months ago, but shortly after that appeared a new version, which fixed it for me. But now that problem showed again.
I hope I could help you with this information now. If there remains something unclear, please feel free to ask me again.
EDIT: I forgot to tell, that we use the Swivl-System with one of the IPads (in case you don’t know what that is: https://www.swivl.com/). The reason I made the JitsiMeet-App update was, that I can’t get the audio from the Swivl-Markers in JitsiMeet, but in Skype it seems to work, at least for test purposes). In JitsiMeet, it seems that I can get only the audio from the internal IPad microphone. Do you have an idea, how to solve this problem, too?