This happends in UE 4.14, I just run some older version (4.10) and there wasn’t any problem.
Some time ago I found some info that it is connected to normals and it is UE4 bug. What is the priority of fixing this bug? Or maybe I misunderstood something?
It’s completely a shadow issue. You can either play with the shadow settings (shadow bias), or use more geometry. Either option will get rig of the artifacts.
