React Typescript useState Hook doesn´t Update by using "setState" method

I am coding a React application and have a problem with the state management.

I added a State "headlineState" which is a boolen which is by default false. Also i have a Callback Method which updates this state.

When the Callback value gets executed, my state doesnt Change.

I implemented a useEffect hool which displays the changes of my state in an "window.alert", and in this hook i see that my state is changing.

But after that, my state returns directly back to false.

function App() {
  
  const [headlineState, setHeadlineState] = useState<boolean>(false);
  
  useEffect(() =>  {
     window.alert("HS changed" + headlineState)
  }, [headlineState]);

  const moveHeadline = (value:boolean) => {
    setHeadlineState(value);
  }

  return (
    <ThemeProvider theme={theme}>
      <div className="App">
        <div className="headerDiv">
          <Header isOnSubpage={headlineState} backBtnClick={() => { moveHeadline(false) }}/>
        </div>
        <div className="contentPageDiv">
          <ContentPage />
        </div>
      </div>
    </ThemeProvider>
  );
}

export default App;