Leveling up skill ghost

Well yesterday I was in a game, and when I leveled my first skill (E) it worked like normal, except that it still had the lvl icon on top of the skill, which messed me up by tricking me into thinking it was an actual one and making me try to lvl it up. This only happens once in a while but when it does, its freaking annoying. If you guys know how to fix it, please do. Thank you.