High noise video during night at F/1.8
Why have you set your ISO as low as ISO200?  You are telling the camera: go ahead and waste the light, I'll crank it up in post-production.  1/50s of exposure does not help.  And you have an f:1.2 lens and use it at f:1.8.  Which is probably sharper in sunshine.  But you don't have sunshine.  Stop telling the camera that it should behave like it has plenty of light to spare (it's not only the ISO but also your other choices) and tell it what it is actually dealing with.  There is no point to choose low ISO values and then magnify exposure digitally: that will give you considerably more noise than if you allow the camera to dial up its sensitivity.  And of course, decrease your shutter speed (what use is the cinematic exposure rule when your principal problem is light?) and open up your aperture.

You have good equipment.  Allow it to participate in problem solving as long as the problems you buy for its respective contributions are smaller than the main problem you are dealing with: a lack of light.