macOS units were experiencing performance issues both authenticating and browsing Hitachi HNAS appliances navigating through any DFS namespace.  This lead to the following issues:

• Long delays mounting shares, browsing folders, and opening files (15s for auth dialog to appear, 15s to connect). 
• Slow file searches
• File corruption
• Disappearing files
• Crashing applications
• Permissions problems
• Locked files and file naming issues
• Failed downloads when using Google Chrome to save gmail attachments directly to server
• Microsoft Office intermittently fails to save documents opened from the server

This was solved by disabling the SMB packet signing.

Read more below!