This appears to have something to do with the way you entered your username. I just fixed the formatting of the link but it's definitely still broken for your channel.
Edit: So I think the value is being URL-encoded and the redirect to the mobile app must not like the encoded slash. I'm not sure how to go about fixing that though.
Edit: So I think the value is being URL-encoded and the redirect to the mobile app must not like the encoded slash. I'm not sure how to go about fixing that though.