UE5_Strange shadows on the border between light and dark

This strange shadow appears at the border of light and dark at the corner of the geometry. I have watched many tutorials and have never seen this situation. I have adjusted a lot of parameters, but this problem has not been solved.

Hope to get your guidance.

Thank you all in advance.

This is called the “terminator problem”, it is ubiquitous in 3d rendering and the easiest solution is to just use more geometry

Anyway, thanks so much!