Hi, the hreflang sitemap is unique, you submit only 1 sitemap for the base language and it must include all other languages relation. So if you submit the sitemap_hreflang_es.xml that's all if it contains relations to other languages.

In the Webmasters Tools the problem could be different and not strictly related to the sitemap, indeed in the 'Segmentation internacional' you could have errors if on your website the hreflang tag is not present in the html of pages.

Best regards
John