Drag and drop not working

Since upgrading to El Capitan I cannot drag and drop properly to my network attaced drive within the same finder window. Holding the file over the destination device for a moment used to show the lower level items such as the drives, folders, subfolders etc. Now it only goes as far as the drive so I cannot drop the file where I want it. Now I need to either copy and paste the file, or use 2 finder windows, one for the origin and one for the destination.

This used to work just fine on mavericks.

I am using Macbook Air (mid 2012)

OSX El Capitan 10.11.4