Wrong username and . .
Tried to follow this link since the passwords differ.
root@ucs-ox1:/usr/lib/univention-server/server_password_change.d# univention-ox postchange
-bash: univention-ox: command not found
However I can view it here.
root@ucs-ox1:/usr/lib/univention-server/server_password_change.d# ls -l
total 36
-rwxr-xr-x 1 root root 2112 Jul 30 15:32 50univention-mail-server
-rwxr-xr-x 1 root root 1294 Sep 22 20:22 portal-server-password-rotate
-rw-r–r-- 1 root root 393 Sep 18 20:08 README.API
-rwxr-xr-x 1 root root 1531 Jul 12 12:17 univention-admin-diary
-rwxr-xr-x 1 root root 1637 Sep 3 09:18 univention-bind
-rwxr-xr-x 1 root root 1314 Jul 23 11:43 univention-libnss-ldap
-rwxr-xr-x 1 root root 1536 Sep 17 13:52 univention-mail-dovecot
-rwxr-xr-x 1 root root 1320 Jul 23 11:43 univention-nscd
-rwxr-xr-x 1 root root 1730 Oct 17 18:37 univention-ox