2d – Bone depth in Unity

I am very new to game development and I am trying to rig a 2D character in Unity 2019 via the 2D animation pack and the IK manager.
This usually works well so far, but unfortunately, I can not get an effective bone depth for any reason whatsoever?
No matter how I configure bone depth for my character, the wrong leg always stays in the foreground.
Helpful tips or a solution to my problem?

Thank you very much in advance.