rejected for compression or grain issues when shooting concrete or old stone. iso 250 no noise or retouching, is the stone throwing off the screening and what can i do about it.

Did you use JPEG to take this image? Looking at it at 100% or even greater - to me is has JPEG artifacts - it looks rather 'blocky' or 'speckly'.

For best results - if you don't do this already is to shoot in raw and do minor adjustments in raw editing software such as Lightroom.

Results are not likely to be so consistent if you shoot in JPEG. Also, I think because there is a lot of detail here - as in the statue, defects are more likely to show up. The reviewers do look at images carefully from what I have gathered since submitting, and this is quite a common theme.

Could you upload an image so we can see the actual what you are referring to? It would then be easier to make a better judgement.

And by the way, there will be some noise even at ISO 250 - but this would depend on the lighting conditions.