Referencing actors problem

Hello guys, i’m developing a game but i have an issue, i think it is a bug on my 4.23.1 or meaby i’ve just did something stupid and i don’t understand: when i place a character or an actor bp in the scene and i click the pick option after i created an actor reference variable inside their blueprint, i CAN actually pick a reference object, and it appears correctly in the detail on the right panel BUT when i open the blueprint, the variable is still null and the picking result only in the viewport, not inside the blueprint.
It seems that the actor in the scene can’t communicate with his blueprint.
i can’t use a newer version because i use substance plugin inside and for the newer version is not avaiable yet.
Sorry for the bad english and thanks for who will help me =)