Issues with "pet" control

When playing a champion like I have become comfortable with controlling his clone by tapping the same key used to activate the ultimate. It works flawlessly most of the time, but it seems there are times when I want to attack an inhibitor (and sometimes turrets) with the clone, and tapping the ultimate key for some reason causes him to walk up to it but not attack. This really throws me off because I do not like holding alt and right clicking. It feels totally weird and it very annoying, and frequently causes me to botch the play I am trying to make.

I want to know if anyone else has ever experienced this and/or are the devs aware that this is a thing? It seems like it should be easy enough to fix.