react-native alert error "Attemp to present UIAlertController

In my react-native application i use some alerts to display messages to the user.

On android everything works fine, but in ios i get following error, every time i try to display an alert:

Warning: Attempt to present <UIAlertController: 0x1030fb600> on <RCTModalHostViewController: 0x1021ad720> whose view is not in the window hierarchy!

i call the alert message via:

this.setState({spinner: true}, () => {  eventHandler    .joinEventById(eventCode, qrHash)    .then((response) => {      this.setState({spinner: false}, () => {        Toast.show('Event Registrierung erfolgreich');      });    })    .catch((error) => {      this.setState({spinner: false}, () =>        funcHelper.showAlert('Fehler beim Beitritt', error, null),      );    });});

i found some solutions to fix it but only for native code, not for the react version.

Can someone give me a hint how i cant fix this or whats the reason for this error