Dynamic actions have 2 different type of conditions.
1) The condition in the "Condition" section
This condition determines if the dynamic action is rendered on the page.
These are only evaluated when the page is rendered. Even more specific only when the page is rendered form the server and not from the cache.
Uses the session state value of page items
2) The condition in the "When" section.
This condition determines if the true or false actions need to be executed. These are evaluated every time the event of the dynamic action is fired.
Uses the client side value of page items.
Looking at the condition type you mentioned you are now using the first one.
If the P0_STATUS changes depending on the user action in the modal page you. And the dynamic action should run depending on this new value you need to use the second one.
Meaning the When condition.