What happened to the 'zoom' function in Vituixcad?

On the previous versions of Vituixcad, eg V 2.0.97.1, you could change the scale (zoom in/out) in the graph window by pressing the Ctrl key and then scrolling up or down with the mouse.

The only thing that happens when you do this now is that the size of the graph window changes, but the scale remains the same.

In the manual you can read...
'Picture can be zoomed in/out with Ctrl + mouse wheel'.
However, this doesn't seem to work anymore.

Is the ability to zoom taken away, or am I missing something? Anyone who knows?