I have a site which uses Drupal core anonymous caching. However, I have noticed a very strange behavior. Sometimes I will load the home page and in the response headers will be the 'X-Drupal-Cache' header. But if I reload the page again, the 'X-Drupal-Cache' header disappears. I cannot understand how this could happen.
What might be the cause?
The response headers also containL
Cache-Control:no-cache, must-revalidate, post-check=0, pre-check=0, which I understand will force the browser not to use a cached version of the page.
Strange thing is that if I access the same page using curl (e.g.
curl -I http://example.com/), the X-Drupal-Cache header appears each and every time.