In my view, albeit a minor point, is the white balance.
For 'Nature23_linnet': the green background has given a slight green cast to the photo, so I would reduce the green tint a bit.
"Nature23_long..': it has a slight yellowish cast, so reduce this a tad.
For the kite, perhaps, the underside of the kite has some noise. I suppose you lifted the shadows a bit and then tried to reduce the noise. Personally, I don't think this is an issue but it could be a reason for refusal.
Post one or two of your pictures “as submitted” here, and we can tell you what we see as defects. There are probably some focussing issues. There may be some artefact issues. And there may be missing details issues:
ABAMBO | Hard- and Software Engineer | Photographer