Horizontal bad overlay geometry in 3d tiles model

Cesium for Unity
1

Hello,
We run into a problem loading local 3d tiles model, it is an overlay horizontal geometry (few polygons) shows in grey color, blocks the model “puddle like” as it’s not covering all model floor but only parts of it.
We definitely see the underneath the geometry if we get close enough and it is there shows correctly.
Other models are loaded as expected, without no bad overlay geometry.
What could be the source of this issue?

Thanks

2

It’s hard to follow what you’re describing. Perhaps you could show us some screenshots?