There is issue that when the model is first opened in Webviewer 2.0 it is always in front of terrain even if some parts should be under terrain. Only if terrain is disabled and re-enabled it shows correctly. See attachment. Is it WAD? How to fix that?
when opened:
After enable/disable terrain:
Example:
Cesium3D tiles example
Service request(7000780650 Closed - QA Audit ) was left unanswered so not sure why toggling the terrain it worked but now Cesium has removed STK terrain at all and it floats in black sky with stars(Defect Report 969151).