CODE server "Could not establish connection to the Collabora Online server."


I want to setup Nextcloud + CODE on a Synology NAS.
My setup:

  • Synology DS918+
  • Use Synology’s Nginx as a proxy to Nextcloud
  • Use Nextcloud in docker (latest)
  • Use Mariadb in docker (latest)
  • Use CODE in docker (latest)

Nextcloud docker:

  • Set local port to 18080

MariaDB docker:

  • Set local port ro 13306

CODE docker:

  • Set local port to 19980
  • Had to set SLEEPFORDEBUGGER=0, because the container always stopped (BUG)

My nginx config:

server {
	    listen 80;
		listen [::]:80;

		# Enforce HTTPS
		return 301 https://$server_name$request_uri;

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

		ssl_certificate             /usr/syno/etc/certificate/_archive/gjD8jZ/fullchain.pem;
		ssl_certificate_key         /usr/syno/etc/certificate/_archive/gjD8jZ/privkey.pem;
		add_header Strict-Transport-Security "max-age=15768000; includeSubDomains;" always;

		client_max_body_size 512M;
		fastcgi_buffers 64 4K;

		gzip on;
		gzip_vary on;
		gzip_comp_level 4;
		gzip_min_length 256;
		gzip_proxied expired no-cache no-store private no_last_modified no_etag auth;
		gzip_types application/atom+xml application/javascript application/json application/ld+json application/manifest+json application/rss+xml application/vnd.geo+json application/ application/x-font-ttf application/x-web-app-manifest+json application/xhtml+xml application/xml font/opentype image/bmp image/svg+xml image/x-icon text/cache-manifest text/css text/plain text/vcard text/vnd.rim.location.xloc text/vtt text/x-component text/x-cross-domain-policy;

		# Pagespeed is not supported by Nextcloud, so if your server is built
		# with the `ngx_pagespeed` module, uncomment this line to disable it.
		#pagespeed off;

		# HTTP response headers borrowed from Nextcloud `.htaccess`
		add_header Referrer-Policy                      "no-referrer"   always;
		add_header X-Content-Type-Options               "nosniff"       always;
		add_header X-Download-Options                   "noopen"        always;
		add_header X-Frame-Options                      "SAMEORIGIN"    always;
		add_header X-Permitted-Cross-Domain-Policies    "none"          always;
		add_header X-Robots-Tag                         "none"          always;
		add_header X-XSS-Protection                     "1; mode=block" always;

		# Remove X-Powered-By, which is an information leak
		fastcgi_hide_header X-Powered-By;
		location / {
			proxy_connect_timeout       600;
			proxy_send_timeout          600;
			proxy_read_timeout          600;
			send_timeout                600;

When i try to set CODE, i got this:

Nextcloud can connect to CODE, it seems a timeout for me.
What is miss?