Panels which are set to auto-hide will open when you click on the tab.
It would be nice to be able to close them the same way.
Just a nice-to-have.
They close automatically when the lose the focus (you click on another panel/window). This behavior is implemented by the 3rd party user interface library and cannot be modified by me.
Just as an aside note, they open the same way. You don't need to click on a tab, just hover your mouse pointer over the one you want to open.