Humanoid "Mirror" Function

Hello, I have a humanoid animation of a character using their right hand for sword, and left hand for shield. My character has most of its animations animated vice versa, with the left hand for sword, and right hand for shield.

I tried to use the "mirror" function, and this does seem to work and flip the animation. However, my props get flipped too. Ex. the sword I had on the left hand now appears on the right hand for whatever reason.

Is there any way to stop this from happening so I can get the correct behavior?