File Upload does only work in Client and isnt working in WebUI

I am using seafile in Docker behind an NGINX.

The File upload is working on my sync, but anyhow, it isnt working in the web UI

When i want to upload a file I get a 404 on the POST req for seafile.domain/seafhttp/upload-aj/…

the log:

Thats my nginx config:

     server_name seafile.domain;

      proxy_set_header X-Forwarded-For $remote_addr;

       location / {
        proxy_set_header Host $host:$server_port;
        proxy_set_header   X-Real-IP $remote_addr;
        proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header   X-Forwarded-Host $server_name;
        proxy_set_header   X-Forwarded-Proto https;
        proxy_read_timeout 1200s;
        client_max_body_size 0;

        location /seafhttp {
            rewrite ^/seafhttp(.*)$ $1 break;
            client_max_body_size 0;

            proxy_connect_timeout  36000s;
            proxy_read_timeout  36000s;
            proxy_send_timeout  36000s;
            send_timeout  36000s;
            proxy_request_buffering off;

       # location /media {
        #    root /srv/seafile/seafile-server-latest/seahub;
         #       proxy_pass;
       # }

    listen 443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/seafile.domain/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/seafile.domain/privkey.pem; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot

    if ($host = seafile.domain) {
        return 301 https://$host$request_uri;
    } # managed by Certbot

     server_name seafile.domain;
    listen 80;
    return 404; # managed by Certbot