Hi !
I Found it!!
The butterfly BP line trace for object is hiting the “Foliage Procedural Volume” because the butterlfies are inside that volume, that is where the foliage are too.
The procedural volume is set to ignore all collision, but it was colliding with the butterflies. Now I set it to NO COLLISION and everything is fine!
Sorry for bother you guys about it, it is not a problem in the line trace, it is just the default settings for collision of the procedural foliage volume that we need to set to no collisions.
Thanks anyway!!!