Windows Server 2019 comes with a secure default config, in this case one Windows 2019 needs access to a samba public share and gives error 0x80004005 when we try to reach the shared folder.

Solution:

Open Regedit

navigate to

HKLM\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters\

and set value to 1 in key AllowInsecureGuestAuth