An inconvinient sphere appears in the scene in VR mode

Saldations to all!
My vr project has camera animations on the matinne (director), when I play play in vr mode for oculus rift, a gray sphere appears in the scene. I observe that this always happens when I create a new camera for a new animation course.
Can you guide me on how to eliminate them?

Maybe this helps you:

Thank you Marco, problem solved!