UPC Scanning Not Working for App?

UPC Scanning Not Working for App?

I have set the preferred scanning mode for Items to UPC (Settings | Preferences | Items).

When I create a package and try to scan the item using the mobile app, it doesn't register. I don't have a desktop scanner to try.

I've downloaded generic bar code readers, and the bar codes are giving the correct information.

Is this a wider issue, or just something I'm dealing with?