Sometimes it will open with a view of some subfolder. Tap the menu icon that looks like a little house to make sure you are at the root of the SD card. Also, did you create your folder as a subfolder? It may not be at the root level.
I can see all of the folders I created. If you aren't seeing some I'd be worried it didn't get created. But I suspect it's more likely you aren't looking in the right place. That's just a guess of course.