If certain files are not available on the Data page they likely haven't finished uploading from the app.
When uploading a form entry that includes media the answer values are usually prioritized and uploaded first. These are generally small in size and thus upload fastest, even on slow network connections. Video files are generally the largest files and take the longest to upload. Audio and photos files, although smaller than videos, are still significant in size - i.e. in the region of 500 kilobytes.
Mobile devices don't often allow apps to run in the background for long before exiting them or setting to sleep mode. Power conservation is a key aspect of our mobile operating system. The less apps running, the less battery life consumed. When the app is in the background or closed, your uploads may not have sufficient time to complete before the app is stopped. In this case, the files will remain on the device waiting for the next time the app is opened to continue uploading.
Additionally, if the app is forcibly closed by the user the mobile operating system will kill the app, which in turn stops any background uploads the app was running.
What can users can do to ensure uploads are completed?
When finished using the app users should push the app to the background instead of killing it. This is done by switching to another app or by hitting the home button on the device. Users shouldn't swipe the app off the 'open apps' view of their device, rather leave it in the apps list even when not in use.
If uploads are slow or incomplete, mobile users can keep the app open and 'awake' in the foreground, or re-open the app when they are next on a faster network connection.
How can users check the progress of uploads?
Users can check file upload progress in two places - on the app and on the platform website.
Using the app, the settings screen shows a count of files that are waiting to be uploaded. If there is no count shown, then all files have been uploaded.
Using the website, the Data area will show the form entries that have been uploaded. You can hoover over each entry row to see the upload status of the files for that entry. This gives you a count of how many files have been uploaded out of the total files for that entry.