I prefer to zoom project (or opened midi or audio event) holding left mouse button on ruler and move mouse up&down.
It worked perfect in every Cubase to version 11 - there is a bug.
When I try to zoom window for first time after I change focus from different window (ie. mixer)- I need to move much further or it not works at all.
The second time I try, it works fine.
It happend in every window with ruler: project, midi event, audio event
It seems that a window without focus (inactive) is not responding to this method of zooming in.
I work in 4 screen configuration, so
I don’t click on the window before to activate it.
Edit: I noticed that after active window change zoom is not working at all when I try to zoom out (left mouse button on ruler with mouse move up)
and zoom in (left mouse button on ruler with mouse move down) has a delay