Route linked to entry does not get translated correctly

I have a news archive: /news/

I want to display a link in each article to "News articles related to {the same person}"
I can’t use /news/{person}, since I am using categories: /news/{cat}

So I created another section: /related-news/
Since this section will not have entries, I created a Route that links to the appropriate template. In the template I use getSegment to fetch articles at /related-news/{person}

My language switcher DOES translate /related-news/ to the other site’s language
but it does NOT translate when there is something after related-news: /related-news/{person}

How can I fix this?