This checkbox prohibits changing, but not creating.
I propose to do this: at the starting stage of the process, set the action
https://prnt.sc/vxegax is configured,
But if you have it set up somewhere so that tasks are automatically created, then it’s better not to put verification in such business processes, or put it on another stage (or make the tasks be created automatically in a different status, which will automatically set the due date and switch the process to the start status), since the task will not be created automatically.