What triggers this issue?
This issue reports all URLs in the website’s sitemap files that return one of the 3xx (redirection) HTTP status codes.
Why is it important?
Sitemap file of a website must list all the pages you want search engines to crawl and index. Besides, Google uses sitemaps data as one of the factors when selecting canonical URLs.
Redirecting URLs in sitemaps send a misleading signal to search engines, instructing them to index the URL that does not return the 200 (OK) response code, but redirects to another URL instead.
This can result in indexability issues on your website.
How to fix it?
Your sitemap files must only include the live URLs that return the 200 (OK) response code.
Replace the redirecting URLs in the sitemaps with the destination URL. If the destination URL is already listed, simply remove the URL that redirects to it from the sitemap file.