Okay, quick take before the details: yes, but it depends on how 'mobi stream' handles cloud sync and subtitle storage. In my experience with streaming apps and media servers, automatic subtitle syncing is possible if the service stores your preferences and subtitle files in the cloud or if you use a central server that feeds all your devices.
I usually think in two buckets: built-in streaming services and DIY media setups. If mobi stream is a commercial app with account-based profiles, look for settings like 'sync preferences', 'subtitle language', or 'save playback settings to cloud'. If those are present and you log into the same account on phone, tablet, and Smart TV, the app can remember your chosen subtitle language and automatically select it on each device. For local files, embedded subtitle tracks in the video (MKV/MP4) will usually carry across, but external .srt files only auto-load if the player finds them (same filename or stored in-app cloud).
Practical tip: check whether mobi stream downloads subtitles for offline playback—offline mode often breaks sync. Also be aware of format quirks: .srt, .vtt, and .ass behave differently; some devices drop styling from .ass. If mobi stream lacks a cloud-sync feature, consider pairing it with a media server like
Plex or Jellyfin which can centralize subtitles and preferences across clients. I’ve had good luck embedding subtitles into MKVs when I wanted absolute consistency across older devices, though that’s more work. Overall, it can sync automatically, but you’ll need to confirm the app’s cloud-sync capabilities and subtitle handling first.