3ds Max Additive animations not playing correctly

Hi,

we're currently trying to export additive animations from 3ds max to unity. Additive animations do work. We've split our character at the pelvis and animatie lower and upper body seperately. We add our additive animation for the upperbody on top. This works, but we noticed that the additive animation for the upperbody does not play correctly and it seems offset.

These two animations are approximately at the same frame and you can see the obvious difference at the arms of the big character(correct anim) and the small character (offset anim).

The character is imported in reference pose. Animations are added via "char@idle" method. Idividually both animations work correctly.

My guess is that the setting in the max/fbx files are faulty but here's the code:

 public void Start ()
 {    
     playerCntrl = gameObject.GetComponent<PlayerController>();

     playerAni.wrapMode = WrapMode.Loop;
     
     additiveAnim = playerAni["walkcycle_upper"];
     additiveAnim.layer = 10;
     
     playerAni["walkcycle_lower"].layer = 0;        
     playerAni["walkcycle_lower"].blendMode = AnimationBlendMode.Blend;
     
     additiveAnim.blendMode = AnimationBlendMode.Additive;

     additiveAnim.enabled = true;
     additiveAnim.weight = 1.0f;

     playerAni.Stop();
 }
 
 void Update () 
 {
     if(playerCntrl.locoState == PlayerController.LocomotionState.WALKING)
     {
         playerAni.CrossFade("walkcycle_lower");
         if(ePlayerAnimState == PlayerAnimations.CurrentPlayerAnimState.IDLE)
         {
             additiveAnim.enabled = true;
         }        
     }
 }

Thank you