How to remove shadow from each tile

CesiumJS
1

My 3Dtiles data includes some parts (tiles).
Each parts(tiles) has shadow like as attached file.
The area of attached file is sea area.
Could you tell me how to remove the shadow?

Cesium3Dtiles_shadow.png

2

Is this the same issue from here? https://groups.google.com/d/msg/cesium-dev/j6xEGaAhkWI/1CX7tvZEBwAJ

Does this shadow move as you move the timeline at the bottom of the viewer?

3

Thank you for your reply.

Is this the same issue from here? https://groups.google.com/d/msg/cesium-dev/j6xEGaAhkWI/1CX7tvZEBwAJ

Yes.
I reposted with sample image.

Does this shadow move as you move the timeline at the bottom of the viewer?

Yes.
I would like to remove the shadow.

4

Can you tell me what data type you uploaded to ion to get your 3D Tiles? If you choose photogrammetry when uploading, it exports it using an unlit material. Here’s an example of a tileset with such a material: