So this looks like a bug on Unreal editor, I raised a bug on their tool for it.
So far there is no solution, if you call parent in a multicast method, you are screwd, even if you restart your game, unreal editor will crash.
I found a workaround for it, basically a parent call is just another method, so instead of calling parent at begining of override, I created a virtual method on parent, and called this virtual right after parent completes his tasks, then childs overrides virtual and continues doing exactly the same.
For some reason, this is not causing issue, and the impact to refactor is really really small. So i´m going with it.
Lesson learned.