skynode problem using different ways to create skynode

[cxhaizxm]

Hi，today i encounter one strange problem. I use the code to create skyNode and let it attach the viewer, i can see double image. i think it is z-flighting, so i open the LogarithmicDepthBuffer, however it is not effect.
But when i use the console to load sky,everything is oky.
i use the osgearth 3.2 osg3.6.5 to test in win10 2017 64.The code and the strange phenomenon photo is below.
I am hoping for your help.Thank you very much.

[gwaldron]

What does your earth file look like? Can you provide a viewpoint where we might be able to reproduce the artifact?