Case Management: Trigger Action Immediately

Hello,

I am using an action in case management to perform some custom logic when the case is set to a particular status, say X. The action is set up to call a method (the EXEC_METHODCALL_PPF BAdI) which houses the required custom logic. Even though I have selected 'Immediate Processing' in the action configuration in IMG, the action is getting triggered only when the case is saved.

There is no schedule condition associated with the action. The start condition is built on the status field (it checks whether the status is equal to X).

What should I do to trigger the action immediately i.e. as soon as the status is set to X?

Thanks.