"Poor Lighting--Poor or uneven lighting, or shadows. White balance may be incorrect."
Is this because I am using CPL filter for my outdoor shots?
It's the shadows in your photos. I'll add this. If you use an on camera flash, for something other than fill flash, they will probably be rejected as snapshots or poor lighting.
Anything with heavy shadows, the subject in the shadows, half light and shadows (even if intentional) will get rejected in most cases for lighting.
Put the Sun over your shoulder, instead of heavily from the side, and you're on the way.