Tap action on button in component shown as Custom Dialog doesn't work

I have a HomePage with a button that opens a component AddPopup as a Custom Dialog; in AddPopup, there's a TextField (without Form wrapper) and two components which are buttons: "Cancel" and "Create":

The TextField has On Submit action to control input value (temporary: for debugging) and update Component State "value" with the input value:

I add actions directly on the "Create" button inside the component (which doesn't really belong to the HomePage): (a) a double Tap to control that the value of TextField is well transmitted via an Informational Dialog, and that works. And (b) a Tap to try to create an item in an App State variable. Fist, I show an Alert Dialog (debugging), then I update the App State, and in the end I close the Custom Dialog:

My questions:

1. Is the value Component State (that holds the value of TextField) really required?

2. The Tap doesn't work (where as the double Tap does!): none of the 3 actions is performed. Any idea of why?

3. How to manage this usecase in the FF philosophy?

Thanks!