Air temp in crawl space seems way to cold in the summer and way too hot in the winter

I have a single variable speed system operating 3 zones (added on). In the Summer, when all zones are operating and all room vents are open, the bypass damper pours cold AC into the crawl space. I thought the bypass was only to open up if too much pressure was detected. So why would it be open. ? The crawl space seems to be cooler than room temperatures through the home. Is this normal and what should be expected?

source https://www.inspectorsjournal.com/topic/18944-air-temp-in-crawl-space-seems-way-to-cold-in-the-summer-and-way-too-hot-in-the-winter/?do=findComment&comment=172901