transform postion trigger problem HELP!

okay well i have a gun....so when i pick it up the tag change and become somethings else, and it tigger collider.enabled=true...it is no more a rigidbody....and it always falowing me by transforming his position to mine every single frame... but my enemies and an other machine systeme in my game they supose to know or see the gunz trigger cuz it's tag it what they should seebut they dont...the trigger doesnt work....WHY?

...it is not my only examples i have many but it just to explain clearly?