...
Schoolbox integration requires creating a SQL user and assigning permissions to access the Synergetic databases and this task is typically performed by the client. Please refer to the Schoolbox Synergetic Integration KB for further details with sample script and health check option to test the SQL user and permissions. https://help.schoolbox.com.au/homepage/495
If using Schoolbox native accounts (not using SAML)
This because of the There is a policy setting on this page here to allow user types to change their passwords in Schoolbox.
https://floreoschoolboxurlhere.gslps.vic.edu.auschool.com/adminv2/lists/roles
You can flick the setting to allow password change for passwords and that should fix it.
...