interesting, I don’t know a whole lot about ProRender but… – the sphere and the Glass are both transparent, I put a checkerboard on the Plane and both are see through. I guess the problem you have is the Face not showing up. It apparently disappears in the render behind the Glass but if you render it with Standard or Physical you can see the Face behind the Glass and in the sphere (you can also see a black patch in the sphere in the same place in prorender as where the better image of the Face shows up in Standard and Physical so it’s working a bit).
My guess (since I don’t know a lot about prorender) is this is a limitation of prorender’s current implementation since they are still working on it or the tiny scale you are working at, the sphere is 0.25 cm in radius and the Glass is 0.001 cm thick. Perhaps Prorender can’t work at that scale (though obviously Standard and Physical can (as can Redshift))
– perhaps someone with more prorender knowledge will know something to tweak in the renderer’s settings