Safariviewcontroller reloads content when open another app then return

Question

I am trying to implement an SSO scenario with using sfsafariviewcontroller. The scenario is below.

1. The user opens the app, and the login page displays in wkwebview.
2. User clicks login button then safariviewcontroller opens the SSO page.
3. The user enters username and password then presses login button in SSO page.
4. For two-step verification, the user enters an SMS-pin in next SSO page and presses the Done button.
5. When verification completes, the user automatically returns with authorized state.

The problem is at step 4. When the user opens messages to get the SMS-pin and returns to the app, the sfsafariviewcontroller reloads the page with the initial URL. So the user cannot enter the SMS-pin.

Why does SfSafariViewController reload the page with the initial URL every time?

The implementation is below.

@interface WebContentViewController()<SFSafariViewControllerDelegate>
...
@end

@implementation WebContentViewController

...
...

- (BOOL)decideNavigationFlow:(NSURL *) url isLinkClicked: (BOOL) isLinkClicked {
....
....
 if(IS_IOS9_OR_GREATER){
            SFSafariViewController *svc = [[SFSafariViewController alloc] initWithURL:url];
         [self presentViewController:svc animated:YES completion:nil];

        }
}

-(void)safariViewController:(SFSafariViewController *)controller didCompleteInitialLoad:(BOOL)didLoadSuccessfully {
    LogInfo(@"#######Initial load completed");
}

-(void)safariViewControllerDidFinish:(SFSafariViewController *)controller {
    LogInfo(@"#######Done pressed");
}
@end