Polygon Bug on Map

Hi everyone.
I’m posting this due to what I think it’s a bug on CesiumJs. I’ve been loading some polygon layers via GeoJsonDataSource and I’ve seen this weird behaviour.
When I call this layers this is whats it’s rendered.

Once I pick Cesium Terrain and comeback to WGS84 it works perfectly fine.

I can’t understand the reason about why this is happen. By the way I’m ussing Cesium 1.76. And I’m initialize the map with depthTestAgainstTerrain = true.

Thanks in advantage.