Is Sitemap Issue Causing Duplicate Content & Unindexed Pages on Google?

[Kingalan1]

On July 10th my site was migrated from Drupal to Google. The site contains approximately 400 pages.

301 permanent redirects were used. The site contains maybe 50 pages of new content.

Many of the new pages have not been indexed and many pages show as duplicate content.

Is it possible that there is a site map issue that is causing this problem? My developer believes the map is formatted correctly, but I am not convinced.

The sitemap address is http://www.nyc-officespace-leader.com/page-sitemap.xml [^]

I am completely non technical so if anyone could take a brief look I would appreciate it immensely.

Thanks,
Alan

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