Looking at your two complete images and the metadata that is available, there are a few things we can see.
The two photos might have been shot in the same place but they aren't comparable ... you aren't comparing apples with apples.
The older shot has a bright sky and a well lit foreground (mostly).
The shot from the newer drone has a section of bright sky, some well lit leaves and a lot of the image is darker or in shadow.
Your Mini 4 photo was shot in program auto where you just left everything to the camera and we can only guess that you probably did the same for the older photo ?
Given a high contrast image (bright and dark areas in the same image) in the newer image, your camera hasn't been able to expose all of the image perfectly and has come up with a solution that's overexposed the bright areas slightly and underexposed the shadows slightly to give something that averages out to be properly exposed.
An experienced photographer would have had to use his skills in post production to do better with the problem you set for the camera.
You cannot compare the two images because they have significant differences in the bright and shade areas.
I suspect there's nothing at all wrong with your new camera at all and it's quite capable of delivering images at least as good as your previous camera.
But a better understanding of some simple photographic principles would help you to use the Mini 4 to its potential.
