No video when connecting through mobile browser

Hello again,
I have a problem using Jitsi Meet with two IPads.
We use our Jitsi Meet instance in an internal network over a router with no Internet connection, with the Ubuntu-Server on an USB-Stick. I have explained our situation in a previous post (Link: https://community.jitsi.org/t/how-can-i-connect-to-own-server-via-ipad-mobile-app/20436).
Recently, our certificates expired, and I thought, it would be a good idea to just reinstall Jitsi Meet, creating a fresh certificate.
I had noted the steps for the install and uninstall from the quick install instructions before, so first I didn’t realize that it had slightly changed.
I reinstalled Jitsi Meet with my notes, which worked well. Now I can make a connection between two PCs.
Then I transmitted the certificate on the IPads, and installed it on them. But I can’t enable full trust for root certificates. That seems to be a “security feature” from new iOS version, which doesn’t trust self-signed certificates anymore. But Jitsi Meet iOS app needs full trust for root certificates to work. Is there any workaround, which makes Jitsi Meet iOS App work with the new self-signed certificate again? We have no internet connection, therefore no domain (only internal IP adresses), and therefore we can’t obtain a Letsencrypt certificate.

I discovered the new function of using Jitsi Meet in the mobile web browser; thank you very much for developing that feature, I think it could make the situation easier for us in the future.
But then I ran into the next problem: now that works with a self-signed certificate, even on the IPads, but each participant in the meeting can only see himself; the other participants are only displayed with an empty screen, but with no video. I have attached our log files below. Can you imagine, what could be the problem here?

Any help would be appreciated; thank you very much.
Greetings, Jan.

EDIT:
Sorry, I’ve forgotten to upload the logs; here they are:
Logs.zip.txt (135.7 KB)

EDIT 2:
Meanwhile, I had restarted the Jicofo, JVB, and Prosody services; but unfortunately with no improvements.

Hello ?? Is there anybody out there, who can help me, please? If you need further information, please let me know, I will see that I can provide you with it.