The receiver’s playback route may not handle the same subtitle format or selection as the app on the sending device.
Why this happens
Playing on a phone and playing through a casting receiver are not always the same decoding path. In a supported casting session, the receiver may fetch and play the media itself instead of simply displaying the phone’s finished picture. Subtitle selection and format support can therefore differ. Seeing a track on the phone does not establish that the television receiver can render it in the same way. This is a more focused observation than saying subtitles have disappeared from the account everywhere.
First identify whether you are using the application’s native Cast option, screen mirroring or another route; those workflows should not be treated as interchangeable. Compare the same item locally and on the receiver and note whether its subtitle menu changes. Google Cast’s documentation makes clear that supported streams and applications can vary, so use the app’s current casting guidance for that combination. If a subtitle format is unavailable on the receiver, changing a phone-only font preference may have no effect. Keep a working direct-player route available when captions are essential to your viewing.
A useful way to work through it
Record whether the session uses native casting or screen mirroring.
Compare the same item’s subtitle choices locally and on the receiver.
Use the app/receiver compatibility guidance rather than assuming phone settings transfer.