Can't get cast/reference to work with trigger BP and actors

I’m having a problem which I find quite strange, I can’t command a Trigger BP to do something, like destroying/Set Actor Location, unless I do an ActorBP reference, and allow to be editable, then I insert the actor instance from the level into the details-default, however, I need to do that without having to do such thing.

Why such thing happens? I’ve saw Matthew Waldstein video using UMG and the variables are not set to be editable.

https://forums.unrealengine.com/attachment.php?attachmentid=127361&d=1485823778