Thanks for playing !
At first, every guard cone was visible at anytime even through wall, it was very confusing so i made it hide if not in line of sight but this method come with the problem you describe :/
I could have use an other method to draw the cone to not go through wall but the fastest one to code was very very bad for game performance and didn't had time to make a better system.
Ikr, the cover's insanely good looking.