It seems that World UI Component is duplicated for each connected client during multiplayer. I don't know what I'm doing wrong or if it's a bug?
If I have one listen server and two remote clients (3 total) all connected clients gets three rendered WorldUI components.

I've tried debugging NoesisGUI plugin source i c++ to see if I can find out what's going on, but I can't seem to find anything useful.
Any help would be appreciated.

I've attached an image to illustrate the problem. Never mind the cubes that aren't replicated.

After further investigation it seems the problem is only present when running multiplayer in editor. Problem disappears when running the game as standalone.
Still, is there some way to make this work when playing in editor?

I'll look into it. Are the actors containing the WorldUIComponents replicated?

The actors are not replicated.

It's easy to replicate the problem by just creating a Static Mesh Actor Blueprint and set it as a cube (for visualizing) and add a World UI Component to it.
Add the Blueprint to the scene and set Replicated to false, then start the game with multiple clients. The World UI component is replicated multiple times for each client while the Blueprint is not.

Edit: The UI components all have the same transform, so it's not visible at first that you have duplicates, in the image in my previous post I moved every separate instance in Z.