Hello,
Have you tried adding interface address on the client instance ?
Update host files on both server and client and make sure all known alias 
names are added to client definations ?
I would also recomend creating client definations on the server with FQDN, 
this would resolve the names to host files first.
Lastly, make sure that the backup server\client is not overloaded and 
having very high utilization during this outbreaks on the Network card.

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