As far of sap hana security is concerned, a password should not be updated with the same definition over again. By default in sap hana, the last 5 passwords cannot be re-used.
However, this protection can be deactivated in order to replace the password with the same values if required. For instance, a technical user which runs backup procedure every day, would fail on next connection if its password is modified.
In order to bypass the security option the "last_used_passwords" parameter has to be set to a zero value before running the password update.
Do not forget to reset the parameter to the previous setting. The procedure will be done using 3 SQL statements.
The first one is to cancel the security policy option. The second one is to update the password. The last one is to place the security option back as it was.