Trigger event on all actors of class from child blueprint

So I have a conveyer belt-like system where I have walls that move up and give the player the illusion they are moving down. Along with the walls, there is a sign that displays their depth (not to scale) and the text on the sign is updated each time the sign’s position is reset back to the bottom of the system. At a certain point, I want the elevator to stop for a few seconds at a certain depth before falling really fast. The way I have my blueprints set up is I have a parent class that has the logic for sliding upwards and resetting its position when it’s too high up. I then made two children classes where one is the wall and the other is the depth sign. I wanted to bind an event dispatcher in the parent class and called the event from the sign child class which would then set the speed of the walls and signs to 0. However, it only sets the speed to 0 on the sign and not the other rocks. Is there any way around this or am I maybe using the dispatchers incorrectly? Any help would be greatly appreciated!