Error ShadowMap Sampling in Additional Lights - URP Unity 2021.1.2

Hello, I am using Unity 2021.1.2. I wrote a custom URP lit shader that is capable of shading multiple lights and casting shadows. It works fine just as my expectation when the point light mode is set to Baked.

However, when I am testing the new Realtime mode, the shading result became incorrect. Is this a bug or an error in my code?