Similar images, one accepted one rejected with artifacts problem, why?

Hi, I'm new to this so am on a learning curve.  I uploaded twenty plus images some were rejected with 'Artifacts Problem'.  Can anyone explain why the attached would be rejected and what I can do to correct these? The boat was ISO400 full frame Nikon D800, the seal ISO1600, full frame Nikon D800 and the caterpillar ISO800 Nikon D500.  The aspect which confuses me is that other images taken at the same settings have been accepted. Processing on all images is minimal.