Character grows in size when playing animation

Character Grows larger

Hi,
As you can see the character grows larger when playing animation. I tried all sort of retargeting combination I could come up with lol The animation was made with/for UE4 skeleton and the character as well. Ironically this is the only animation that gives headache. Running, idle and kicking are fine.
Any idea why is that and how to fix it?

Thanks in advance