Hello !
I think you have assumed Actors/Blueprints = Prefabs. They, however, not.
Your blueprint is base class and when you spawn instances of base class - all of them will have basic properties.
There is a lot of different ways to modify this behaviour, for example you can modify “Construction script”, which is called whenever object is spawned in world:
Just setup behaviour you want to see in construction script and then spawn your cards as usual