If you are unable to see all of the files/folders that are available in the Web Viewer, we suggest performing a Reset Sync.
1) Hold your finger on the circle Sync Status icon in the top-right of the app
2) Tap Reset Sync
3) Browse to the folder that contains what you're looking for and wait for the app to sync the folder, usually 30 seconds
If this does not work, you can also exit the app and restart it.