OK, I'm a little confused
In that last post, the second crop (third image) looks to me like the RAW file with color noise reduction set at zero - there is both magenta and green noise visible; this leads me to wonder if the first crop (second image) is actually the preview visible when you're in LR's Library module. For these examples, if you're not doing so already, you should be in the Develop module to see what the final result will be.
For the processed image, what are your luminance and colour noise reduction settings? Also, are you increasing the exposure, bringing up the shadows or black level, reducing contrast etc.?
My recommendation would be to start with an image that is well exposed (I assume at least one of your examples is well exposed) - one that doesn't require an exposure or shadows boost (since pushing exposure will lead to increased noise in the shadows). Set your colour noise reduction to +25, and initially set the luminance noise reduction to zero (since your issue is colour noise, no luminance).
It is possible that, with previous cameras, you have been using colour noise reduction at +25 without realising it, since this is the default setting. If, somehow, the default when you import your GRII images (or in any user presets you're applying) is setting the colour noise reduction to zero, you'd see this effect.