Welcome to the Forum, @Aliikane! 
I agree with @Resist that it’d be interesting to see side-by-side comparisons under different lighting conditions.
No, it’s hardware (physics, optics).
Yes, it can be mitigated to some degree, depending on how you set the camera and where it’s aimed in relation to where the sun’s position is likely to be (so it’s kind of a moving target). The white part with the slight curve in the Backyard Right Cam view is part of the camera body’s face, and the camera’s picture is showing that because it’s reflecting off the glass of the window in front of the camera and being picked up by the lens. Some users have darkened that using things like paint or Plasti Dip, and you can do other things to minimize the reflection from the window that the camera picks up:
- Get the camera lens as close to the window as possible/practicable.
- Provide a dark background behind the camera to minimize the sunlight that’s reflected back against the window’s interior surface. I read somewhere in the Forum the suggestion to hang a black T-shirt behind the camera.
- Wyze makes a Window Mount specifically for this purpose, but it doesn’t give any angle (like if you want the camera to look up or down or to one side), so there are DIY solutions you can find online, including downloadable models for 3D printing that could be customized to suit your application (if you have access to something like that), and I imagine this is also something you could find in an Etsy store, though I haven’t searched.