ATEM Mini Extreme ISO - Green Screen grainy video solution?

I am using a green screen with the ATEM Mini Extreme ISO. I need to be able to demonstrate what is on my computer screen. So I PIP myself and demonstrate the screen.

Despite having high end lighting by Godox, a high quality green screen material, a 4k DSLR Camera etc that I end up with a grainy image of myself in the output.

I also tried recording directory to the USB SSD and found the results the same. I am using this HDMI splitter as part of the process https://www.orei.com/products/uhds104-u ... i-splitter which if memory serves me correctly provided a way for me to see things on a live monitor

Does anyone have a suggestion of a better way I can do what I'm doing to achieve a better quality end result?

Adjust the settings. Blackmagic has a tutorial on YouTube.

Thank you. There are a sea of tutorials out there. Can you by chance pass along the one you might be referring to?

With a well lit and correctly exposed image then you should get a clean key.

If you ONLY see the grain on the foreground when you have sampled the CHROMA then you can adjust the key adjustments to dial out the noise.