I've resubmitted updated sitemap with like 3k more links and it's been 2 days it's not updating.. Is this an issue or should I wait?
there is no issue but it take some time to update because if in the sitemap has link with 1k plus then it take time mostly 3 day or more for update.
For best effect, make sure the sitemap file only contains real non-duplicate and non-thin-content page URLs