Can't close open apps from top

Windows 8.1
I "think" all open apps should be able to be closed by dragging them from the top of the desktop screen to the bottom. Most of mine don't, like Firefox, IE, Control Panel, others. Windows Mail does, however. When I drag to the bottom, they just sit there on the very bottom.
I used to be able to close them this way, but perhaps I messed up somehow. Any thoughts on this? Shouldn't ALL apps be closed when dragging down?
Thanks.
EW

 

The "Metro" IE , and Mail should, but, anyone, correct me if I am wrong, but I don't think the others are Metro Apps, so will only close in the normal (previous OS) way.

 

One way I have discovered to close an app is to point your cursor in the bottom left of the screen (not sure what the panel that opens is called), a panel will open showing all of your open apps. Hover your mouse over the app you want to close, right click on it and a menu will open. Click on "close" and that is it.

 

Davehc, I think you've got it. After a bit more research and tinkering, I concur with your reply. 8.1 is a bit different from 8.0, and this is one of those differences. Thanks.