After uploading the initial form definition, I go to the Testing tab, scan the QR code, download the form, and fill it out. Upon submitting I get an Error: Generic Exception: Error: A resource already exists with sha value(s) of ... and the upload fails.
Is it possible that you've attached the same media file twice for two different questions? I seem to remember we've identified some kind of limitation there before that can turn up in a testing context.
If I design my form silly enough to ask for multiple mandatory photos of the same thing, could users be tempted to choose the same photo from their gallery for repeated media questions?
For now they will need to be different images. Can the data collectors edit those submissions and take a picture of a piece of paper that says "same as before" or something like that?