The "green dot" appears to be lens flare. There are some techniques for reducing lens flare. There are a few tutorials online and they use variations of the following:
In the Color page of DaVinci Resolve, select the clip with the lens flare and go to the Color Wheels & Match section.
In the Color Wheels & Match section, increase the Gain of the RGB channel to decrease the intensity of the lens flare. You can also adjust the Color Wheels to change the color of the flare.
If the lens flare is still visible after adjusting the Gain and Color Wheels, you can try using the HSL qualifiers to isolate the flare and then use the Power Window to draw a mask around it.
In the Power Window, you can use the Color tab to adjust the color and intensity of the flare, or use the Opacity tab to reduce the visibility of the flare.
If the lens flare is still visible after adjusting the Power Window, you can try using the Clone Stamp or the Paint tools to manually remove the flare by painting over it with surrounding pixels.