Clear cache by:

  1.  Open settings
  2. Scroll down till you see Fitvault and tap On Fitvault
  3.  Toggle Clear Cache
  4. Make sure you allow access to Background App Refresh

If that doesn’t work you will need to completely delete the app:

  1. Tap to open Settings.
  2. Tap General.
  3. Tap iPhone Storage.
  4. Find and tap on Fitvault.
  5. Tap Delete App. Do not select Offload App, as this keeps the data you’re trying to delete.
  6. Tap Delete App again in the slide-up prompt.
  7. Reinstall the app from the App Store.