Hello @CycleDude
SMB will use NTLMv2, by default, when using an IP address in the UNC path or the system is not domain joined;
SMB will try to use Kerberos authentication when a hostname is used and the system is domain joined, In this case Look at the Kerberos traffic on TCP port 88 to make sure there are no Kerberos errors when getting the token.
Best Regards
Karlie
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