I have this problem too, from console
Error: Can't contact LDAP server
Mar 07 08:27:26 tank smbd[13672]: Error in the pull function.
Mar 07 08:27:42 tank smbd[13672]: [2020/03/07 08:27:42.332696, 0] ../so
urce3/passdb/pdb_ldap.c:6540(pdb_ldapsam_init_common)
Mar 07 08:27:42 tank smbd[13672]: pdb_init_ldapsam: WARNING: Could not
get domain info, nor add one to the domain. We cannot work reliably without it.
Mar 07 08:27:42 tank smbd[13672]: [2020/03/07 08:27:42.332801, 0] ../so
urce3/passdb/pdb_interface.c:180(make_pdb_method_name)
Mar 07 08:27:42 tank smbd[13672]: pdb backend ldapsam:ldaps://192.168.
0.250:389 did not correctly init (error was NT_STATUS_CANT_ACCESS_DOMAIN_INFO)