This is a weird one. I've attached a picture below. I can right-click and get a menu on the BDAG entry or any entry in the folders above that one. I cannot right-click and get a menu on anything below the BDAG or any of the other folders below it.
This affects all the folders below that entry. Once I get down to items that aren't in folders, it works fine for the first 8 items that aren't in folders, and then it stops working for any below that.