Looks like double encoded url changes the content inside the html file.
RewriteRule ^/about/test.html(.*)$ /test/test.html$1 [NE]
rule works fine, but for double encoded it adds %20 in html file
Eg. Title Test%20Test%20Test%20
is there a way to clean the html file us mod_rewrite or this issue is not related to Apache+redirect
Got answer from .htaccess url rewrite and removing %20
this rule may affect all , instead use %{REQUEST_URI} apply for required uri.