Same issue for me too, was working fine but started doing this earlier this month, 7800x3d, 3080ti, LG C2, latest win11 update, DDU and latest Nvidia game ready drivers. I have tried different old HDMI cables and bought another new HDMI2.1 one.
After trying to calibrate the monitor I noticed that it isn't actually a green tint, but a total lack of the blue channel, that makes everything look green or magenta.
Edit the C2 doesn't have the "PC Dolby vision" option in the menu as the G5 above has, or if it does it isn't in the same place and I couldn't find it.