Can't Key 6K Raw in fusion, footage is all bugged out!

I bought a Blackmagic pocket 6K camera.
I was doing some greenscreen test and I can seem to get a key out of it.
I don't have the perfect light but it should be able to give me a goodish key. Using a canon C300 MKii the key comes almost perfect, using my Galaxy note 10 the key come okish (surprisingly) Using the pocket is unusable.

Any dark areas can be filled and there is nasty noise all around. I had the ISO at 500. The cleanplate won't recognise the green even after grading it and making a comp. Delta key will remove the great but then I can't fill the foreground.

Going into Fusion Studio using primatte keyer I can actually key it but the edges are awful and since I can blend it with delta keyer I can't get good edges.

In the delta keyer using the replace more to source helps filling in the dark areas better but it's still rubbish.
I exported the footage as a 12bit DNX file and tried in after effects but I have the same problem!

Is there something wrong with the camera??? 6K 12bit raw should be good!! I saw some people's green screen examples using a pocket 6K and it all looks bad. I had to sell my main cam Canon C300MK II. I am really worried.

Any help is welcome,

Thanks!

Image of issue
https://imgur.com/nuQmtOn

Can you post a short example?

Uli Plank I got what the problem was. The footage was too noisy, I tend to get lazy when testing ideas, my old cam coped much better noise wise. After denonising the footage it worked much better.
I forgot I filmed at 120 fps which is heavily cropped and it makes the noise really bad.