Jitsi insecure web socket (Nginx problem)

Hey together,
I have some trouble with my jitsi installation. I installed it using the docker selfhosting guide. I can access jitsi on localhost as intentendet, but I get an error (Connection not secure) when accessing it from my domain, using a reverse proxy.

Can someone help me with this problem? I have no idea what the problem is…

Nginx config:

server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;

    server_name meet.*****;

    location / {
        proxy_pass http://localhost:8991;
    }

    location /xmpp-websocket {
    	proxy_pass https://localhost:8443;
    	proxy_http_version 1.1;
	proxy_set_header Upgrade $http_upgrade;
	proxy_set_header Connection "upgrade";
    }

    location /colibri-ws {
    	proxy_pass https://localhost:8443;
    	proxy_http_version 1.1;
    	proxy_set_header Upgrade $http_upgrade;
    	proxy_set_header Connection "upgrade";
    }

    ssl_certificate /etc/letsencrypt/live/*****/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/*****/privkey.pem; # managed by Certbot
}

The only things i have ever changed in my jitsi config (the .env file) are this lines:

# Exposed HTTP port
HTTP_PORT=8991

# Exposed HTTPS port
HTTPS_PORT=8443

# System time zone
TZ=UTC

# Public URL for the web service (required)
PUBLIC_URL=https://meet.*****