Shadow artifacts with animated material

Development Asset Creation
1

Hi all,
I am trying to use a couple of vegetation models in my scene that have each animated material for the wind (via normal maps animated).
Unfortunately every time i switch on the wind effect the result is a strange animation with some dark artifacts.

I suppose the shadows are not updated during the changing normal inside the 2 sided foliage material.

Somone know how to fix this problem?

Here a video showing my problem.

thank you.

2

I just realize that the issue is caused by the ray traced shadows enebled in the rect ligth object.
If i put DISABLE on the ray traced shadows the problem disappear.

Anyone know how to use the ray traced shadows without having this problem?

thank you.