An Actor in the map with a Widget Component is setup to show a SceneCapture2D via its assigned widget blueprint.
The scene capture looks fine when stationary, but when the camera moves (via character movement, and by camera/spring arm rotation) visual artifacts appear over the entire “screen” (i.e. just the Widget Component), with more movement seeming to lead to a higher density of artifacts on the Widget Component.
The Render Target texture (on the right, below) always looks fine, regardless of the issues I see in the world viewport whilst moving the camera.