Geckolib attack animation won't work, see the attached image

Basically, I want to make this golem play the animation once every 3 times he attacked

See the procedure I made right here:

https://imgur.com/a/1k9UVuK

The problem is it won't play the animation. 

I tried changing the animation block to "Deal Damage to Event/target Entity" and it deals damage to me so I assume the NBT works fine.

I also tried the animation block on the "When right clicked on entity" and the animation works fine too, the golem smashes when I right clicked.

But it won't work on this attack procedure, can it be that the animation block doesn't work with "Source entity" component?

I'm out of ideas, please help, thanks! :)