Tested it again today on 061.121.227.03404 and it scans with no issue from the 7556 to Server 2003-2008R2-2012-Win10.
Wireshark traces show it using SMB2 to both Win 10 and Server 2012, didn't have time to trace the others.
Call Xerox, get 2nd level support, they will probably require an Altboot since I can't replicate your issue in their own test environment, they will need a config sheet, Server information and likely will want a Wireshark trace of the failure (They can help you do that if need be)