Zoom in/out using scrollwheel not working in EA 15.1! What could cause this?

[mmo]

For some strange reason the zooming into/out-of a diagram doesn't work for me! According to the manual (and also my memory) this is supposed to work by pressing the Ctrl-key and turning the mouse wheel up and down. However, after installing the latest version (v15.1.1529) this doesn't work anymore! Also with Ctrl key pressed the diagram pans up and down instead of changing the zoom factor. This makes editing some diagrams almost impossible!

What could cause this and how to fix this?

PS: Needless to say that my mouse's scroll wheel works perfectly fine and the very same zooming into/out-of gesture works fine as one would expect in other applications (e.g. Office apps like Word or Outlook or in all my browsers (Edge, FF, Chrome)).