Yup… I have a reverse proxy. Chromecast in Emby works, Chromecast in JellyFin doesn’t. Really weird.

iPhone has no Play Store. I got the app from the AppStore for iPhone, no luck, chromecast does not work.

Chromecast in JF never worked…
When I click the chromecast icon in JF “Play On” (top right) I get “Google Cast Unsupported”.

How did you manage to get it working?

Windows browsers such Firefox, Chrome, Vivaldi, Brave have the same issue. It’s not OS or device related, it’s how Chromecast has been implemented in Jellyfin.

https://github.com/jellyfin/jellyfin/issues/6840#issuecomment-1042905147

I’m also the developer of a local media server, and I’ve easily managed to bypass the Chromecast client-side issues by doing a server-side discovery. Now no matter how I access my media content, I can always send it to a Chromecast, because the CC and my server are on the same network, so the CC can easily be discovered over Avahi/Bonjour/mDNS. Then it can be the server itself to provide the client with a list of discovered players, not necessarily the other way around.
The fact that there’s no server-side logic to manage the Chromecasts, and instead we rely on the client to discover them, explains why things are so broken. Why not provide a server-side CC scan logic as a backup for users who don’t use Chrome on Android but run the server on the same network as the CC, instead of relying on such a brittle client-side implementation?

This is why! It’s a crappy implication…

https://github.com/jellyfin/jellyfin/issues/6840#issuecomment-1042905147

JF has no proper chromecast support… ☹️😤