CPU IPR shows different results from production render

[lukepenry]

I posted this in the general forum but only got 1 answer that was a dead end so thought i'd try my luck here.

When i use the cpu IPR it looks different to when hit final render. I am not mistakenly using the gpu either. i really can't get my head around it.

the Shiny sphere is the IPR and the rough sphere is the production.

3ds max 2020
vray-next 4.20
CPU amd threadripper 32 core
gpu 2080ti
128gbram

cheers

[^Lele^]

To be fair, the issues are a few, if those are meant to be IPR and "offline" render thereof.
In the right image, there is visible tessellation on the bigger sphere's specular, and thew hues and colors of the bluish rock don't math at all with the image on the left.
Do you have a scene you can share?