Nextcloud can't login and Logo not loading

Nextcloud version (20.0.1.1):
Operating system and version (Raspbain/Debian Buster):
Apache version ( 2.4.38):
Nginx version (1.14.2):
PHP version (eg, 7.3.19):


Hello, i am trying to set up my Nextcloud behind a reverse proxy (NGINX). Yesterday i got it working , but it just stopped giving me encoding errors today . So i added proxy_set_header Accept-Encoding “”; to nginx. Now, I can access the login page, but the logo is not loading, i can see a random # above and i can’t login. But the URL changes to the default dashboard and the logs report, that the user logged in and the content is loading…

config.php:
grafik

server {
  listen 443 ssl;
  server_name xxx.net;
    ssl_certificate mypath/fullchain.pem; 
    ssl_certificate_key mypath/privkey.pem; 

location  /nextcloud/ {
   rewrite /nextcloud/(.*) /$1  break;
   proxy_pass http://192.168.178.40:4000;
   proxy_redirect http:// https://;

proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
proxy_set_header X-Forwarded-Host $server_name;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection “upgrade”;
proxy_set_header Accept-Encoding "";
proxy_http_version 1.1;
add_header Front-End-Https on;
}

I don’t know why it worked perfect and now not. In chrome i can see these errors:
grafik

I really hope you can help me, I get a little bit frustrated, because i am trying so many hours to get this NC working. Grafana works fine behind the reverse proxy , no problems.