Apple's 6splus front camera reflects light when shooting people.

Reflection is normal, because there are many reflective substances around, including clothes, glasses and so on.

Because the pixel of the front camera is not high, there will be noise and reflection when shooting at night.

The photos taken by the iPhone during the day are of high quality, even for the front camera.

If it's not the phone camera, then the solution is to take pictures at night as much as possible. It's best to take pictures from above your oblique front, and there should not be too many background light sources, otherwise it will be easy to reflect light.