Check that you have used the full domain host name (for example: j5serverdev.full.domain.name) during the setup process. The full domain host name should be used, otherwise the active directory will not accept the connection. The log files should look like this if DEBUG logging is on:
2020-04-08 07:30:33 INFO [+0000002916 CP Server Thread-7]: Attempting Kerberos Authentication at HTTP@FULL_DOMAIN_NAME
2020-04-08 07:30:33 DEBUG [+0000002916 CP Server Thread-7]: There was an issue with the received Kerberos ticket.
If the j5 Server is not reachable with its domain host name there might be an issue with the DNS Server. The host name must be added to the DNS Server for Kerberos to work correctly.