Animation socket problem heelp

Hi, I imported infiltrator character from epic’s demo and I want to try to give him some weapons so I placed a socket with a preview mesh on his hands in the idle_rifle animation but when I change animation, for example I open aim_rifle the socket is messed up. Probably this is a quite frequent problem but I don’t really know how to fix it. Obviously If I try to manually fix the socket in the broken animation, the other one messes up.

Here I place manually my weapon

111597-immagine2.png

Here you can see what’s happen to other animations

111596-immagine.png

EDIT: ok I placed a FABRIK node in my animbp to lock on the weapon to my left hand but even If I place my left hand in the right way in the anim bp viewport when I play it is messed up. This is what I did:

1)Go in the anim bp

2)open animgraph

3)go in the state machine and open idle/Run rifle state

4)place between final animation pose and rifleblendspace fabrik node

5)setting up fabrik node

6)pose my left hand in the right way on the rifle in the anim bp viewport

After these steps when I try it ingame, the left hand is shifted

111720-immagine3.png

but when I’m the anim bp’s viewport it seems ok

111731-immagine2.png

Here are my fabrik settings:

111719-immagine.png

Did I miss something?