Google's John Mueller confirmed on Twitter that having a Sitemap file that lists pages that are duplicative to others, won't necessarily cause ranking issues for your site. It might confuse Google when it comes to crawling but it should not impact rankings, John said.
John was asked, "how quickly could a sitemap that accidentally allows for duplicate content across an entire site cause issues in your rankings?" He replied, "I don't think it would cause ranking problems." He explained that it might cause confusion with "crawling as an early effect" but added, "I don't see how this would cause immediate ranking changes for the whole site."
Here are those tweets:
I don't think it would cause ranking problems.
— johnmu: nothing is permanent, use 302 always 💫 (@JohnMu) October 29, 2022
I think you'd primarily see confused crawling as an early effect, i don't see how this would cause immediate ranking changes for the whole site.
— johnmu: nothing is permanent, use 302 always 💫 (@JohnMu) October 29, 2022
So while it might be inefficient and cause some crawling confusion to have such duplicative URLs in your sitemap file, it should not impact your Google Search rankings.
Forum discussion at Twitter.
