how do I get full diagonal animation weight with blend tree

Hello I am new to animation and I'm struggling with Unity's blend trees.

This blend tree in my example does give me the result I'm looking for when I preview the animation and drag the red dot around. However when I use my gamepad joystick and push it diagonally, the X and Y parameters only reach 0.7, and not 1. How do I get the full animation weight of 1,1 when input is diagonal? Any help is greatly appreciated! Thanks.