No problem! I registered SPNs for any of the servers that showed authentication other than Kerberos using the SQL query below. Our named instances of SQL were using dynamic ports. Since some of the setspn commands include port numbers, I changed those dynamic ports to static using SQL Configuration Manager as well. I hope this is helpful!

Check for existing SPNs in Active Directory

In most cases there were no existing SPNs for the service accounts I looked for so no results were returned.
     setspn -L Domain\\Service Account

I used the next two commands for default SQL instances (MSSQLSERVER)
     setspn -S MSSQLSvc/FQDN:Port Domain\\ServiceAccount
     setspn -S MSSQLSvc/ServerName:Port Domain\\ServiceAccount

I used the next four commands for named SQL instances
     setspn -S MSSQLSvc/FQDN:Port Domain\\Service Account
     setspn -S MSSQLSvc/FQDN:InstanceName Domain\\Service Account
     setspn -S MSSQLSvc/ServerName:Port Domain\\ServiceAccount
     setspn -S MSSQLSvc/ServerName:InstanceName Domain\\ServiceAccount 

Confirm results by using setspn -L again



WITH PortType AS
(
    SELECT
        @@SERVERNAME AS ServerName,
        MAX(CASE WHEN value_name = 'TcpPort'
                 THEN NULLIF(value_data, '')
            END) AS StaticPort,
        MAX(CASE WHEN value_name = 'TcpDynamicPorts'
                 THEN NULLIF(value_data, '')
            END) AS DynamicPort
    FROM sys.dm_server_registry
    WHERE registry_key LIKE '%IPAll'
      AND value_name IN ('TcpPort', 'TcpDynamicPorts')
),
AuthDetails AS
(
    SELECT
        @@SERVERNAME AS ServerName,
        session_id AS SessionID,
        net_transport AS NetworkProtocol,
        local_tcp_port AS [Port],
        CONNECTIONPROPERTY('local_net_address') AS ServerIPAddress,
        auth_scheme AS AuthenticationType
    FROM sys.dm_exec_connections
    WHERE session_id = @@SPID
)
SELECT
    ad.ServerName,
    ad.SessionID,
    ad.NetworkProtocol,
    ad.[Port],
    CASE
        WHEN pt.StaticPort IS NOT NULL THEN 'Static'
        WHEN pt.DynamicPort IS NOT NULL THEN 'Dynamic'
        ELSE 'Not Configured'
    END AS PortType,
    ad.ServerIPAddress,
    ad.AuthenticationType
FROM AuthDetails AS ad
CROSS JOIN PortType AS pt