Hey guys. My apologies for the delayed response.
Yes, this normal. By default, Quick Cache does NOT cache _GET requests. However, you can change if you need to.
Please log into your WP Dashboard, and go to:
Quick Cache -> Don't Cache Query String GET Requests
Don't Cache Query String GET Requests?This should almost always be set to True, unless you're using unfriendly Permalinks on your site. In other words, if all of your URLs contain a query string ( /?something=something ), you ARE using unfriendly Permalinks, and you should update your Permalink options in WordPress® immediately, because that also optimizes your site for search engines.
That being said, if you really want to use unfriendly Permalinks, and only if you're using unfriendly Permalinks, you should set this to False; and don't worry too much, the sky won't fall on your head
It should also be noted that POST requests ( forms with method="POST" ) are always excluded from the cache, which is the way it should be. POST requests should never be cached. CLI requests are also excluded from the cache. A CLI request is one that comes from the command line; commonly used by cron jobs and other automated routines.
* Advanced Tip: If you are NOT caching GET requests ( recommended ), but you do want to allow some special URLs that include query string parameters to be cached; you can add this special parameter to your URL &qcAC=1 to tell Quick Cache that it is OK to cache that particular URL, even though it contains query string arguments.