Why left click walk to location when I'm playing with WASD configuration

Title says it all.

I don't understand why clicking moves my character when I'm playing with WASD. Is there a way to cancel it? Because I'm having hard time on trials because of traps while fighting with enemies sometimes. I'm not moving with WASD but I missclick to the ground with my projectile skill and my character just walks there and triggering traps, which is not a very good gaming experience imo.