please someone help me spawn a VFX at a weapon (especially with my third approach)

I’ve been trying for more than a week to spawn visual effects at my weapon to simulate the buff that the player can get in the game.

My First approach was to trying to directly cast to the weapon then spawn the visual effect at the socket directly from the player blueprint
the first approach is spawning the visual effects at the initial location where the weapon was placed in the level not at the socket

my second approach is casting to the weapon then triggering an event in the weapon blueprint and the event supposed to spawn the visual effects at the socket both approaches are not working

my third approach is to put a niagara effect component in the weapon blueprint and activating it when I trigger the event.
but it is not working correctly,
if I toggle Auto activate in the niagara component detail from the beginning, then the niagara effect actually spawn in the corrected place at the weapon socket, and when I move the visual effect move along with me.
however when I don’t toggle the auto activate the blueprint as shown in the third approach picture, the VFX is not activating
i think the third aproach is the best but why i cant activate it normally from the blueprint ?