Html link extension to Custom Post Types

Personally, I would just to a 301 redirect in the htaccess that redirects pages to the url without the .html

The code below should work for you:

RewriteCond %{THE_REQUEST} \.html
RewriteRule ^(.*)\.html$ /$1 [R=301,L]

If adding the code provided above to your htaccess did not fix the problem then I am afraid I do not know of another situation. Maybe someone else here in the support forum will be able to make a suggestion!

[ Moderator note: when to modlook: https://make.ww.wp.xz.cn/support/handbook/contributing-to-the-wordpress-forums/modlook-and-tagging/ ]