Link to URLs without a trailing slash in the links on your page.
It is links that define URLs.
DO link to /en/ (with slash), and DO link to /en/news (without slash).
It is the rewrite that takes that URL request and finds the place inside the server to get the content from.
It is the redirects that make the browser request a different URL when they ask for the wrong one (e.g. when asking for .php URLs).