Oh, I think I found it @TheRavensCurio .
If you just Add a Noise Node (like Voronoi), that Node is automatically Selected, but that isn’t reflected in the UV Editor, if you then start switching between the Nodes, the Image in the UV Editor changes accordingly, just as you described.
Never noticed that before, I must admit…That is indeed a bit of a weird feature (or is it a long-standing bug?).
