Gh5 video noise

Panasonic users I will ask for your help I am new on the video world I use Panasonic gh5 25fps 100mbps 8bit manual Wb Every few meters with a gray card Olympus 8mm fisheye lens with close Aperture Between (5.6 -11)+1.5 step keldan red filter +2 x8 12000lm keldan light All the clips come out with lots of noises and grains over 10 meter depth Especially on the sides and far places it should be noted that I turned the (i dynamic range) mode to high mode and (i resolution to high)I do not know if this is what causes the noise I use at low iso no more than 800 iso and color profile vivid Does anyone know the problem?