We are experiencing some unusual behaviour regarding Dispatcher. If we make a request to a page that should not be cached according to out dispatcher rules, and the request contains query parameters, then the response is missing the Cache-Control header.
We would expect to see
cache-control: max-age=0, no-cache, no-store, must-revalidate
but we do not see the cache control header at all.
This is occurring regardless of whether the query parameter is in the list of ignored query params or not. If we remove the query params then we see the normal cache-control header as expected.