Server-Sided Part.Touched not firing because part has a different position on client

Hello, I have made a script that creates fake arms for first person, and changes the Part0 property of Right Arm.RightGrip to the fake arm to weld the tool to the fake arms model instead of the real character.
But I have a problem here because the server cannot detect collisions for the part now, I tried this with Classic Sword and it won’t fire Handle.Touched when the FPS script is activated.

With FPS script disabled:


With FPS script enabled: