I am developing an app in iOS 16 ARC and I am trying to persist a string value inside NSUserDefaults like this:

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<UIImagePickerControllerInfoKey,id> *)info {
    // Retrieve the selected image
    UIImage *selectedImage = info[UIImagePickerControllerOriginalImage];
    // Dismiss the image picker controller
    [picker dismissViewControllerAnimated:YES completion:^{
        NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
        NSString *base64String = [self getImageBase64:selectedImage];
        [defaults setObject:base64String forKey:@"imageBase64"];
        // [defaults synchronize]; //has no effect
        NSLog(@"retrieved: %@", [defaults objectForKey:@"imageBase64"]);
    }];
}

However, the NSLog statement always prints a blank string. I originally thought this was related to memory management and the base64String falling outside of scope once the method completed execution, but it doesn’t seem to be working even when I try to reference it within the same scope/function execution.

Any help would be greatly appreciated!