If have done a split and have two editor windows open and one or both of the windows is wider than the ruler, with light gray space to each side of the text area, clicking in the light gray space fails to set that window as the active window. One is forced to remember to click within the narrower text area rather than anywhere in the window.
I have forgotten if one can turn the ruler off, so am unable to report if that happens with ruler turned off.
I'm a Scrivener enthusiast and experienced in PC/network support... but I am not a Scrivener expert. And I'm still editing on my first book. So take any opinion or advice I offer with a large grain of salt.