Snap reveals Port

I’ve setup a nginx snap nextcloud combination for collabora which works perfectly fine, besides the fact that snap reveals the changed port of nextcloud.

So I’ve set the Nextcloud ports with this command:
snap set nextcloud ports.http=81 ports.https=444
and my nginx config looks like this:

server {
        listen 443 ssl http2;
        listen [::]:443 ssl http2;
        server_name cloud.domain.com;

        client_max_body_size 0;
        underscores_in_headers on;
        ssl_certificate /etc/letsencrypt/live/cloud.domain.com/fullchain.pem; # managed by Certbot
        ssl_certificate_key /etc/letsencrypt/live/cloud.domain.com/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
        location ~ {
                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;
                add_header Front-End-Https on;
                proxy_headers_hash_max_size 512;
                proxy_headers_hash_bucket_size 64;
                proxy_buffering off;
                proxy_redirect off;
                proxy_max_temp_file_size 0;
                proxy_pass http://127.0.0.1:81;
        }
}

I’ve already added the domain to trusted_domains but it still redirects to cloud.domain.com:444. Is there a way to prevent this?