Seems like pretty standard browser/app handover behaviour to me, although the app not working is a massive fail and should - hopefully - flag up automatically as a critical issue on Medium's side.

Obvious suggestion but not made in snark: uninstall the medium app? I’ve had to do that for lots of poorly developed apps or apps developed not in sync with the web frontend.

Edit: it is a bad link and I can see why this would happen if you had the Medium app installed. It’s a “branded” Medium post (i.e. appears on the Netflix-owned domain) but clicking the link redirects you to medium.com then redirects you back to the cname.