If an installed app on the OnePlus smartphone no longer functions properly, it may help to clear the cache of the corresponding app.
This will delete services and temporary files that may have overlaid each other and therefore cause application-related malfunction.

Note: Clearing the app cache does not delete existing files, only the cache.

Android 10 | OxygenOS 10.0
Clear app cache -  Open the  Settings
Clear app cache -  Tap on  Apps & notifications
Clear app cache -  Tap on  See all apps
Clear app cache -  Choose an  app
Clear app cache -  Tap on  Storage & cache
Clear app cache -  Tap on  Clear cache
  1. Open the Settings
  2. Tap on Apps & notifications
  3. Tap on See all apps
  4. Choose an app
  5. Tap on Storage & cache
  6. Tap on Clear cache

OnePlus Instructions