If a mobile visit is Completed, but it is not appearing in DND or your scheduling system then it has not transferred off of the device. The visit may not transfer due to poor connection state or because you are collecting signatures and signatures have not been collected.
If the user is in a poor connection area and they do not see the word Transferred on the Visit in History, then they should log into the app when they are in a better connected area. The visit will transfer.
If the signature is missing, then they should collect the signature and the visit will transfer.