Confirm where playback started
Note whether you opened the item from downloaded movies or from its ordinary online details or Stream Library page. The same title can be visible in several places while using different playback modes. A successful offline start is evidence about the saved phone copy, not every television route.
Keep the rental’s actual deadline in mind while investigating. Changing the screen does not establish a new viewing period. Avoid deleting the only completed offline copy before deciding whether an online route is suitable for the planned session.
Use the published online casting entry point
The help places the Cast action on the movie details page or Stream Library for supported mobile routes. It separately qualifies AirPlay and Chromecast device support, so check the relevant current guide and application rather than assuming the two receiver types are identical.
Most importantly for this symptom, both guides exclude downloaded movies from casting. Repeatedly searching the saved file’s player for an absent button does not establish a hardware fault. If an online session is intended, inspect that authorised route while connectivity is available.
Choose the viewing route before relying on the download
For a trip without a dependable connection, plan to use the saved copy on its supported mobile device unless the service documents another offline screen route. For a television session with connectivity, inspect the current native-app or supported casting offer for the actual device.
If an eligible online cast still fails, report the sender, receiver, app version, title and whether playback was online or downloaded. That final distinction is central to this documented limitation. Do not assume that copying the protected download to another device or buying the movie again changes the Cast support of the saved-file mode.
Questions about this guide
Does offline playback on the phone prove TV casting works?
No. The published guides explicitly exclude casting downloaded movies.
Where is the documented Cast entry for online viewing?
The guides name the movie details page or Stream Library on the supported mobile route.