Hi @eric.koester,
IFS (split files) should not require manual intervention, but Amazon has shown instability in downloads which causes problems for transparent IFS download/reassembly.
Right now you are probably going to have issues with Amazon no matter what since they are being slammed by all of the users trying to migrate off their system after the announcement that they are getting rid of their unlimited storage plan.
See here for more details:
https://forum.odrive.com/t/amazon-drive-is-dropping-their-unlimited-storage-plan-on-2017-06-08/2565