Did you set to send scanned images only when the mobile device is connected to Wi-Fi?
When [Only send and receive data when connected to Wi-Fi] is set to on in ScanSnap Home ( → [Settings] → [Network settings]), data can be sent only when the mobile device is connected to Wi-Fi.
If Wi-Fi connectivity is not available, sending scanned images is suspended. When the mobile device is connected to Wi-Fi, the images are automatically sent to the cloud service.
If the sending status of scanned images does not change even after the mobile device is connected to Wi-Fi, wait for a while with ScanSnap Home started.