IK Foot on Custom Character

Hello, I made the same question on ue4 forum over a month ago but there is no feedback, mayby here I will find some more help.
I have a question, how to make IK for some custom character. I would like to trace footsteps.
There is no problem with copied function and ue4 characters.
But the problem shows when I’m trying to use it with some custom character. The screen will show more:

When I’m sending foot distance from ground as Right/Left Foot Effector Location then foots are spreading instead of going up. Im setting distance to ground as X (I tried also Y and Z but result is the same).
Where should I start to looking for errors?
And mayby someone know what is exactly the Joint Target Location in Two Bone IK?