The pics are too contrasty and the quality of the photo (especially for stock photos where the quality has to be high) isn't very good, unfortunately. You can see some noise when you zoom in to 100%.
The lens would have made a difference. I have this lens as well actually. It's not good. I wouldn't bother to submit any photo to Adobe Stock taken with this lens. It's not sharp enough. Shutterstock has different acceptance standards to Adobe as far as I can tell. They, ( I don't think) are as picky.