This is because your internal dispatcher is http, where when you redirect the page via
RewriteRule ^/content/abc/us/en/(.*)(.html)$ /$1.html [R=301], you are actually redirecting the users to the http endpoint.|
it will redirect
o http://abcd.com/support.html
o https://abcd.com/support.html (because an apache rule or Azure frontdoor rule forces all requests to go to HTTPS)
to solve this problem, you can include the https protocol in the redirect target
RewriteRule ^/content/abc/us/en/(.*)(.html)$ https://%{HTTP_HOST}/$1.html [R=301]
Ideally, you should set an environment variable that includes the protocol and hostname,
https://%{HTTP_HOST}/$1