You have a DNS problem because by default, a Microsoft Distributed File System Namespace (DFSN) root referral reply to a DFS root referral query is in NetBIOS name format (\<Server>\<Share>).
So, you have to enable FQDN DFS open a Powershell and do :
1)Obtain the list of all name spaces
Get-DfsnRoot - ComputerName YOURSERVERNAME |Where type -NotMatch "Standalone"
2) remove all DFS name spaces
Remove-DfsnRootTarget -TargetPath OBTAINEDInStep1
3) enable the FQDN
Set-DfsnServerConfiguration -ComputerName YOURSERVERNAME -UseFqdn $true
4) Restart the DFS service:
Stop-Service dfs; Start-Service dfs