Sitemap: 403 and 404 errors – Kindly Help

Hi,

I recently changed my permalink from example.com/date/sumple-post to example.com/sample-post and redirected all the URLS to suit the new permalink.

A few days later I checked my Search Console and noticed that the number of indexed posts had gone down from 140 to 94 and there are three errors on my sitemap: posts posted on March and Feb 2014 had 404 errors and the posts posted on Sept 2015 had 403 error.

I am using the latest version of WordPress and Google XML Sitemap
My blog URL is: https://reedfashionmag.com/
Webserver software is NginX
W3 Total Chache for caching and Yoast plugin for SEO.

Kindly help.

Thanks.

https://www.ads-software.com/plugins/google-sitemap-generator/