"Shadow Clones" of landscape material textures appearing when paintning

Hi there, I have an issue where, when I paint on my landscape, a shadow, identical in shape, appears elsewhere on the map. It always appears in the same place when I paint in specific spots. Here is a youtube video showing the issue. Any help at all would be greatly appreciated.

Does it go away once you recompute the materials or close/re-open the level?

IF not, then it’s likely due to either RTV which is repeating a section somehow, or something you are doing within the material that causes that mirrored repetition.

Also Possibly a result of the engine being a constant bug…

Thing is - go near the “Shadow” is it just a shadow or a different material?