Though I do not know the specific solution to your problem, I can possibly offer tips to get you to a solution.
Both, STCameraPoseInitializerStrategyGravityAlignedAtOrigin and STCameraPoseInitializerStrategyGravityAlignedAtVolumeCenter need a gravity vector. Are you sure you are using the correct gravity vector when using those constants?
Also, have you seen the function -updateCameraPoseWithGravity:depthFrame:error: under the STCameraPoseInitializer class? Maybe it can help?
Let me know what you come up with!