OnePlus
Enable System-Wide Captions auf OnePlus
OnePlus phones running Android include a system-level captioning feature that is separate from the subtitle toggle inside streaming apps. It applies to apps that support Android's captioning API, so results vary depending on which apps you use.
You find the setting under Open the Settings ➔ Tap on System ➔ Tap on Accessibility ➔ Tap on Caption preferences ➔ Enable or disable Use captions.
Once Use captions is switched on, you can go to Set the Language, Text size or choose a Caption style to define how subtitles look across supported apps. This includes text size, font style and background options for the captions.
Turning this on does not disable an app's own subtitle menu, for example inside a video player or streaming service. Those two systems work in parallel, and an app with its own subtitle engine will usually keep using it instead of the system captions.
If videos in a specific app still show no subtitles after enabling this option, the app likely does not support Android's captioning API and needs its own in-app subtitle setting instead.

