This seem to happend because the Shooter Game skeleton is built a little different from the normal mannequin one. The first one has 2 spine bones while the mannequin one has 3. To fix this go to the retarget manager for the Shooter Game skeleton and set “spine_03” to “b_spine1”.
I also have the guy in a T-pose to match my retarget skeleton, though it should still work with a A-pose.
Seems to look fine to my eyes atleast.
