Scene layer packages in ArcGIS Pro can be published to ArcGIS Online as web scene layers. In some cases, web scene layers published from a scene layer package fail to display when opened in Scene Viewer.
This issue occurs when the ground layer (Terrain 3D) in Scene Viewer overlaps the scene layer. The ground layer, also known as the elevation layer, provides base heights for other layers in a scene and defines height values across the extent of a scene.
Deselect the ground layer option by unchecking the Terrain 3D box in Scene Viewer.