Axes Grid not visible with Ray Tracing

Hi, when using the Ray Tracing I can’t get any of ‘Axes Grid’ or ‘Data Axes Grid’ to show.
The Color Legend/Color bar and Orientation Axes are always visible but as the ‘Enable Ray Tracing’ is checked the Axes Grid disappears.
Tried with OSPRay and OptiX, in the last 5.8.1 RC1 and 5.8.1 RC1-872 compiled.
Is there any way to use them or it is a bug with Ray Tracing?