Self-Cast bug

I recently started playing Lissandra, and I almost immediately realized that the self-cast function doesn't work if you have your cursor on an enemy champion. Seeing as how self casting can be hotkeyed (which mine is) I deliberately press another key when I want to self-cast and that should override who my mouse is on. My mouse is most likely going to be on an enemy in this moment as I am casting other spells within a fraction of a second of my ult and often it is in a group of enemies. This is definitely a bug in my opinion and I would definitely like it fixed, it would not affect those who don't use hotkeys for self-cast.