I can't see the tooltip when hovering over the storage bar

I am using iTunes 12.3.1 on Windows 10, and when I hover my mouse over any of the areas of the colored storage bar at the bottom of the itunes screen, there is no tooltip to show how much storage is used by either Audio, Photo, Apps, Books, etc. This used to work in earlier versions I had of Itunes. How do I get this functionality back?

Rob