Update sitemap link on sitemap widget on main dashboard is not working.

Update sitemap now on the sitemap widget on the site main dashboard is not working as it was earlier. When clicking the link it is not showing any message like updating and done updating and it also shows the date format incorrectly.
Like It was last updated on February 17, 2018, at February 17, 2018. Google: Last notified on February 17, 2018, at February 17, 2018.
Bing: Last notified on February 17, 2018, at February 17, 2018. Ealier it used to show like last updated on February 17, 2018, at 1:23 am.