My some files are rejected due to the reasons - submission closely resembles content already available on Adobe Stock

If you’re submitting a series of infographics at the same time, that could explain the flags for “similar content.” 

Try uploading a mix of distinctly different content. Space your infographics a few weeks apart. 

This is what Adobe Stock says about ‘similar content.’ 

Take what you will from it:

• https://helpx.adobe.com/stock/contributor/submit-your-content/submit-distinct-content/distinct-content-submission-best-practices.html
• https://helpx.adobe.com/stock/contributor/submit-your-content/submit-distinct-content/distinct-photo-submission-best-practices.html
• https://helpx.adobe.com/stock/contributor/submit-your-content/submit-distinct-content/distinct-vector-and-illustration-submission-best-practices.html

Hope that helps.

Welcome to the club. This is a common reason for rejection, with the likelihood that titles and keywords, more so than the image itself, are the result of such rejections.

Sorry, but we will not be able to help you. For over a year we have not had clear guidelines on what this rejection reason entails.