After a site migration my rankings got hit very hard. basically my traffic went to zero, a reason for this is that many pages have not been indexed correctly, at least they dont appear in serp when i search them. According to the coverage report in GSC all my 70 URLS have the status ""indexed not submitted in sitemap", instead of "indexed and send".

This could mean that google has not read my sitemap and indexed the pages via other means. Could it be that they listed them as duplciate content and dont get indexed correcctly for this reason?

Question: How do i get the correct status in the covere report ("indexed and send"). Should I reupload the sitemap?