This is what I meant, notice the prompts when I ssh to sensor 6.2.3 and 6.4.0
6.2.3
Last login: Wed Jan 8 09:55:18 UTC 2020 on ttyS1
Copyright 2004-2018, Cisco and/or its affiliates. All rights reserved.
Cisco is a registered trademark of Cisco Systems, Inc.
All other trademarks are property of their respective owners.
Cisco Fire Linux OS v6.2.3 (build 13)
Cisco ASA5516 v6.2.3 (build 83)
Last login: Mon Jan 20 10:01:01 UTC 2020 on cron
>
6.4.0
Last login: Fri Jan 17 19:48:51 UTC 2020 from x.x.x.x. on pts/0
Last login: Mon Jan 20 10:47:05 2020 from x.x.x.x
Copyright 2004-2019, Cisco and/or its affiliates. All rights reserved.
Cisco is a registered trademark of Cisco Systems, Inc.
All other trademarks are property of their respective owners.
Cisco Fire Linux OS v6.4.0 (build 2)
Cisco ASA5516 v6.4.0.4 (build 34)
admin@XXX-FIREPOWER01:~$