This is a somewhat weird issue, but the thing is that when trying to select folders and subfolders within a drives tree, I am unable to see it.
I guess a picture is better than a thousand words..

As you can see the graphics looks a bit weird and I am not able to "open" the drives to find subfolders, no matter where I click.
The "EXTSG5TB" has some folders selected I think and that is why you see those two small black "things" inside the sqare.
Ideas anyone?