Retargeting: Why wont my character stay anchored to the ground during animation?

how can I keep my character from floating or anchor my characters feet to be anchored during animations?
I created a mesh in Blender and rigged it to have the same skeleton as the UE4 Man… I created IK Rigs for both UE4 Man… and my character. I also created the IK Retargeter. I imported my mesh and set it up. The animations seem to work with the exception of floating up a bit and the feet not being anchored to the ground on “crouch to stand” and “jump from stand” animations.
Sorry, I couldnt upload the video of the sequence showing the UE4 Man… and my character.