In all previous versions of Cubase you can toggle the mixer open/close with a single key stroke. In C7 pressing F3 first brings the mixer into focus. It requires a 2nd keystroke to close the mixer. Is this intended?
Personally, I much prefer the way it has always worked. Fewer clicks, faster work flow.
But I suppose if you want to use the mixer and it is hidden behind another window, with the old behaviour, it would have required an additional keystroke -once to close it and once more to re-open it with the mixer now being at the front.
But have you tried to open the mixer, activating the main project window and then hitting F3? Here it behaves exactly as Steve H. described in the first post.
::Confirmed::
OK, yes I can reproduce that, only for hiding the mixer though, and only when, as you say, the Project window has the focus - not the Cubase main window. It seems the first click removes the focus from the project window, then the second click does it’s job hiding the mixer.