The issue of SMB shares are not accessible using the UNC path after installing Windows 10 update 1903 was addressed in FluidFS v6.0.400016 (MR640) which was released in October 2019, and is generally available.  This FluidFS v6.0.400016 requires Storage Center OS 6.5.x - 7.2.x Helpful Tidbit: Make sure to pause replication before starting any firmware upgrades on FluidFS.  
Yesterday our Windows 10 machines were upgraded to the 1903 release of Windows 10 & since then are unable to connect to our FS8600 NAS unless SMBv3 is disabled.  Are there are there other settings that can be adjusted to allow for our Win10 1903 clients to connect to our FluidFS NAS head without disabling SMBv3 completely? Others appear to have experienced this issue: [URL] Thanks!Eric
Fluid FS v6.0.300135 & Windows 1903 unable to connect to SMB shares using SMBv3