Hojinnim, I think you may have switched two thrusters and plugged them into the wrong outputs on the Pixhawk. Please verify that your motors are plugged in to the right outputs, as numbered here. If you look at the diagram, you can see that if you were to switch motors 2 and 3, forward and lateral movements would still work correctly, but then when you try to yaw, the motors’ thrust will cancel out. This would also be the case if you were to switch motors 1 and 4.
-Jacob