As agreed with the team we will work on these topics via emails. I will, however, share a concise reply here as well.
 Permissions of folders in NFS can, on occasion, be different from source. This has been identified as a bug and we are working on solving it. Additional sync operation may fix that issue, but not with 100% certainty.
I will have an update with timeline for fix soon, but we gave it a high priority.
 Scanning happens before the copying. When the error is scan failure it is most likely failing to read from the source.
It may happen intermittently, but as you mentioned, the next sync will retrasmit that.
We did see that happen when targetting EFS as EFS can be slow to react (Depending on what is the EFS configuration.
 The broker has internet access and is sending meta data to the backend of the SaaS service of CloudSync.
It sends messages to the SQS queues that are critical for the sync operation.
Your data is NOT being sent to the backend but is copied directly.
Other kind of traffic are Kibana artifacts that allow us to determine the status of the transfer.
Potentially this can be reduced, but we don't recommend it.
I will send the information and more over email as well.
Manager, Cloud Solution Architecture