Varnish not caching

Good morning,

Site is http://www.hessel.org

Varnish is not caching, and we cannot save WordPress menus (receive 503 from Varnish cache server).

Here is the Varnish status report. How do I determine what is causing the issues?

– Varnish is running but cannot cache.
– You’re using a Custom Varnish IP that doesn’t appear to match your server IP address. If you’re using multiple Varnish servers or IPv6, this is fine. Please make sure you’ve properly configured it according to your webhost’s specifications.
– Because CloudFlare is running, you may experience some cache oddities. Make sure you configure WordPress for Cloudflare.
– Your site is compressing content and making the internet faster.
– The “Age” header is set to less than 1, which means you checked right when Varnish cleared the cache for that url or Varnish is not actually serving the content for that url from cache. Check again (refresh the page) but if it happens again, it could be one of the following reasons:
That url is excluded from the cache on purpose in the Varnish vcl file (in which case everything is working.)
– A theme or plugin is sending cache headers that are telling Varnish not to serve that content from cache. This means you will have to fix the cache headers the application is sending to Varnish. A lot of the time those headers are Cache-Control and/or Expires.
– A theme or plugin is setting a session cookie, which can prevent Varnish from serving content from cache. You need to make it not send a session cookie for anonymous traffic.
Something is setting the header Cache-Control to “no-cache” which means visitors will never get cached pages.
– Something is setting the header Pragma to “no-cache” which means visitors will never get cached pages.

Thanks,

Terry