I noticed that my zoom function seemed a bit slow, but then I realized that when I use the mouse, there is this delay before the game start zooming the camera.
When using the keyboard hotkey (the pluss and minus on numerical keyboard), the camera zoom pretty much instantly for me and so there is no dealy.
The difference is striking and if everyone has this issue, then I hope there might be a solution for fixing it so that there could be no delay when zooming with the mouse.