Photo rejected for technical issue, but...

I see aliasing, like with an over sharpened picture. Your horizon looks razor sharp to me, and your remark lets me think that you pushed the boundaries too much.

With Prime, you mean DXO's denoising technology?

FYI: all pictures are reviewed by humans, but sure, the quality requirements are more stringent than at the time as the technology (both hardware and software) gets better.

Nice photo. The water is underexposed. The sky is a little noisy. The birds need to be removed. There is one spot that has been corrected however can stilll be seen. and there is fringing (halo) everywhere.

Looking at the photo at 100 - 200%, it does seem quite noisy.  I would clone out the birds as well because right now they just look like artifact spots above the horizon.

You might try neutralizing the white balance and attempt to re-submit.

https://www.adobe.com/creativecloud/photography/discover/white-balance.html

Unfortunately, difficult lighting conditions due to storms or other factors are not considered by Stock reviewers.   All photos are judged by the same criteria regardless of conditions, equipment, or other challenges.

Better luck next time!