Hi,
I found a solution.
Short bug correction instructions:
1. Set up a scene with clouds
2. Add a large Box to the scene going to the horizon line.
The height of the box does not matter much. But be sure to be above the line where the cloud clipping error occurs.
3. Assign the Corona Volumetric Material to the Box and adjust the Distance parameter (select the desired value based on the render). The color of the Scattering Color choose gray or white.
Watch more in the video.