Changing the skybox in Unity with Octane

[TranSystems]

OK, I'm running out of ideas for how to have a sky show up in the PBR viewport using Octane in Unity 2018.1. I've tried putting it in the PBR Render Target in every slot that looks halfway appropriate, and in the Main Camera, and in the Lighting Panel - nothing but the blue -to-white gradient shows up in the render. The sky shows up in the Editor and Game windows just fine. Anybody have success with this?

[Xhed]

Can you try the settings combination as I set it in the attachment?

[TranSystems]

Thanks, that seems to be working well enough. The different sky choices seem to have wildly different and extreme effects on exposure of the frame. Some look fairly normal, others blow everything out almost to white.