How can I make player's character arms collide?

How can I make the arms of an R6 model collide with each other instead of overlapping?
I’ve tried to mess with collision groups but it did not do what I expected.

Here how it looks when I load the game:

And here how it looks after I walk around:

<game name=“MyGame”>
<asset name=“R6_M_Arms_Mov”>
<binding part=“R6_M_Arms_Mov”>
<clip name=“idle” ref="/assets/animations/character/R6_M_Arms_Mov.FBX/idle" />
<clip name=“walk” ref="/assets/animations/character/R6_M_Arms_Mov.FBX/walk" />
<clip name=“walk_fast” ref="/assets/animations/character/R6_M_Arms_Mov.FBX/walk_fast" />
<clip name=“run” ref="/assets/animations/character/R6_M_Arms_Mov.FBX/run" />
<clip name=“run_fast” ref="/assets/animations/character/R6_M_Arms_Mov.FBX/run_fast" />
<entity name=“player”>
<component type=“CharacterComponent”>
<parameter name=“Height” value=“1.7” />
<parameter name=“Radius” value=“0.25” />
<parameter name=“StepOffset” value=“0.45” />
<parameter name=“CanJump” value=“true” /