Troubleshooting Jitsi login as moderator fails on Debian10 behind Nginx Reverse Proxy

Hello everybody,

first of all I want to summarize my setup:

During the installation I used my DynDNS domain with my wildcard certificate. I added a new vdomain for Nginx point to my virtual machine with Jitsi. And I also finalized the setup with the secure domain setup.
So far it seems to work but I’m unable to gain moderator rights. When I enter my credentials I always get another login window.

In the logs of prosody I can only find things like:

Client disconnected: ssl handshake error: sslv3 alert certificate unknown (tried the communicated fix)

Authenticated as z2ju29knlimycshq@<my.domain> (seems like I become a guest user)

I’m not sure which logs I also could share with you. So sorry in advance if I forgot something! Feel free to ask for more details. I’m really looking forward to any help you’ll send! (And of course I searched for other related topics over here but nothing could help me yet)

Kind regards,

If you revert the secure domain, is everything OK?

Sadly not. Should I do a new clean install? (do you have a detailed step-by-step instruction?)
I also get kicked out of the meeting when I join via the local ip address. So I guess there are some issues with the basic install.