My high-quality AI-generated images keep getting rejected for "Quality Issues."

Quality comprises much more than just file size. You must zoom in 100-200% on each image and inspect carefully for artifacts and AI drawing errors. On people images you must look at fingers, ears, eyes, nose, teeth, mouth, skin texture, hair, clothing, buttons, button holes, clasps, jewelry, etc. 

Hello,

As these are 'photos' one also needs to look at the tone. So, in my view the white balance in most of them needs adjusting - although it is a minor adjustment.

E.g.: Orginal

And a minor adjustment:

Make the image slightly warmer.

The indoor shots are a bit green. You have to adjust the skin tones and overall tone.

E.g:

These images are judged as photos - because they come under this category.

Quality issues have nothing to do with file size. Examine your assets at 100% or more and fix any errors before submitting.