Questions about 3DTiles and shadowMap

I have generated shadowMaps, which I hope can be overlaid on buildings, similar to viewShed, but I find that in 3DTiles Next,shadowMap cannot be overlaid. I also tested the 3DTiles data for an earlier version and the effect I wanted was achieved.

So, I want to know what causes this problem.

Thank you!

↓↓↓↓↓↓↓ 3dTiles data from previous versions ↓↓↓↓↓↓↓

↓↓↓↓↓↓↓ 3dtiles next ↓↓↓↓↓↓↓

As a side note, in the sandbox example, you need to left-click twice to determine the start and end points of shadowMap!

How should these serrations be solved?