I am using an MDM solution to set Dock settings of macOS device.
When I set "autohide-immutable" key as true, "Automatically hide." button should be locked. But in our case, "Automatically hide" button is not locked until we change, or click some other option in the Dock Settings.
After clicking an option in Dock Settings, "Automatically Hide" button gets locked.
The problem in here is that we can also click "Automatically Hide" button and change it's value before it is locked.
https://developer.apple.com/documentation/devicemanagement/dock