When requesting over REST the content types of a given group, the response is always a miss.
1. Make sure HTTP cache is enabled
2. Request twice the content types of a group: http://localhost:43082/api/ezp/v2/content/typegroups/1/types.
3. Verify if the response was cached. As far as I'm concerned, X-Cache is always a MISS, while we can expect a HIT.