Pro2017-Layers Menu in Tray: Can't scroll through!

[blackdogsketch]

In most of my models I have a long list of layers...longer than the menu typically can display at once. I use center mouse wheel to scroll thru to bottom or top as needed. In 2017, my ability to scroll is very limited. Once in a great while I can get it to happen, but most of the time scrolling does nothing and I have to sue the up/down arrows. No problems in 2016 and the mouse does not appear problematic in any other programs.

Any thoughts on this? So far I am not impressed at all with 2017