So, in the Translation retarget option of the animation. Change Pelvis “animation” to “Skeleton”. The root are now moving with the characters… (Or character is animated but stay in place) So when we merge the both animations, is finally corect.
But we lose the real movement “in the ground” of the motion capture and have to manualy move the character with Transform point in the sequencer.
Because in my case, Root have no data. That why everything bug.