No defect - just typical lens flare. See how bright it was to the left? (at least that's what it looks like from your sample) That's what can happen when there is a bright light source such as the sun close to the edge of the frame. If you're using filters this is another reason to get good quality multi-coated filters, to reduce the chance of this happening. Lens hoods also help with this, but I am not sure if there is a good one available fort the M2P yet. If you position the drone so that the light source is not directly in the image or just outside the frame, you will see that this disappears.
Anyways my $3,000 DSLR lenses do this if I am not careful - totally normal.