Welcome to the Cesium Community!
This may be caused by a setting specific to the FME software itself. There has been other users who experienced issues with shading on 3D Tiles exported from FME software before, such as here.
Welcome to the Cesium Community!
This may be caused by a setting specific to the FME software itself. There has been other users who experienced issues with shading on 3D Tiles exported from FME software before, such as here.