wrong encoding of / in genre urls

when clicking on a genre of an artist that has a slash in its name (e.g. hip hop/rap) I get redirected to

https://stats.fm/genre/hip-hop/rap which yields a 404 and loads forever on mobile.
the expected behaviour would be to encode / as %2F like this:

https://stats.fm/genre/hip-hop%2Frap (which works btw)