Virtual texturing with transparent material


I am making the Earth, it’s just a sphere with very larges textures for the surface (several 16K textures). It works well,

But when I add a second sphere, a bit bigger for the clouds. My clouds are just using a surface shader with opacity. The issue though, is that when I have these clouds, the earth 16k textures wont display correctly anymore. Either they will appear to have a very low resolution (like 128 or 256), or worse, my earth shader will even use a wrong texture of an other object in the scene.

Any idea how I can fix that?