Hi Joakim,
I had the same issue, and unfortunately the only thing you can do is to pay 200£ to IKinema to have a custom retarget for your character.
Alternatively, but it takes ages and the results are hit and miss, is to modify the Json file inside the retarget folder, since if you open it with a Json editor, you can tweak the position and rotation of each joint, shifting their position.
I tried to do that, but is very time consuming and tedious, so it’s up to you wheter or not give it a try.