Is water system problem?

An unknown shadow is created over my ocean.
This shadow follows the camera.
But there is no object in my world that can create a shadow like this.
I am using UE4.26.2 water system.

How can I solve this?

This shadow follows the camera.

Can we see the hierarchy of the camera pawn? Or the hierarchy of whichever actor handles the camera?

This is the same for editors without pawns and cameras.
Rotating the light also rotate the shadow.
but i haven’t any objects. I checked while switching objects in hierarchy.

Sorry, no clue. Definitely post in the forums if you haven’t done so.

Today I reproduced the same problem with WaterPlugin’s WaterTestMap.

Increasing the DistanceFieldShadowDistance(or Dynamic ShadowDistance MovableLight distance) for directional lights creates unknown shadows.

For reference, I set the DistanceFieldShadow distance to 80000.
I posted it on the forum. thanks for advise.