Redirect 301 – Help! My website is automatically 301 redirecting even new publications

Google just issued a warning when I tried to manually index a new post. "When we tested a sample of URLs in your Sitemap, we found that some URLs redirect to other locations. We recommend that your Sitemap contain URLs that point to the final destination (the redirection destination) instead of redirecting to another URL."

This is because virtually ALL the URLs of my site have been redirected without my knowledge; I have only manually redirected a handful through an add-on (Redirect).

That I have to do? I do not want to lose my no. 1 ranking in some publications that have been going up for a while. I noticed that several redirects are for attachments in a publication that I do not really need. Could you just delete that post, reinstall the add-on and solve the problem? Or will Google keep trying to find the deleted post? Thanks for any help or guidance.