Photos not accepted to Adobe Stock Photos

You need to post the picture here to have us a critical eye on the asset. But may be reading about the riquirement and the technical issues will give you the answer. Mostly they are atifacts, noise, washed out colours, white balance, subject out of focus etc.

If you are new to stock, you should consider these resources: https://helpx.adobe.com/stock/contributor/tutorials.html
Please read the contributor user manual for more information on Adobe stock contributions: https://helpx.adobe.com/stock/contributor/user-guide.html
See here for rejection reasons: https://helpx.adobe.com/stock/contributor/help/reasons-for-content-rejection.html
and especially quality and technical issues: https://helpx.adobe.com/stock/contributor/help/quality-and-technical-issues.html