V-ray distributed rendering

When rendering on my PC, V-Ray does fine. However, it would be ideal to render on a second one to speed things up.

We set everything up to render on two PCs (mine and a colleges) but when the VFB updates, there’s some strange banding. We had assumed this would go away over time but when one of these bands disappears, another appears somewhere else.

No matter what we do, the result remains the same. I’ve attached an image to better explain what I mean.

Any help or advice would be greatly appreciated.