I think you'll find that's just "noise" from the camera. All digital cameras suffer from that to some extent but it's only noticeable in low light conditions. It's not a fault
Can you see it on well lit subjects outside? What drone are you using?
I keep the settings below zero (contrast -1, sharpness -1 and saturation -2) since I use an editing software for fine tuning the footage.
I just realized once the same effect when I accidentally pushed the sharpness,
P4 has 4K camera, hence no need to increase sharpness in the camera settings.
That's quite a different scene though.
Indoors light levels are much lower even on a bright day.
The problem with your example clip is it doesn't go full screen like youtube.
Can't really see any detail.
I'd recommend you view some of Frederick Hagan's videos on what you should be seeing as well as his post-processing ones. The ND filter one might help you too as it shows the tree effects he gets to compare yours to.