LAContext evaluatePolicy not showing TouchID prompt

We are using LAContext evaluatePolicy API to show the TouchID prompt in our App.

• If we place our finger for authentication, then we can see the TouchID prompt and it completes the authentication.
• What's even more strange is that when we can't see the pop-up window, then shake the device can make it appear.

😐

A simple project with code below:

#import "ViewController.h"
#import 
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad {
    [super viewDidLoad];
}
- (void)viewDidAppear:(BOOL)animated{
    dispatch_async(dispatch_get_main_queue(), ^{
        LAContext *context = [[LAContext alloc] init];
        [context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:@"xxxx" reply:^(BOOL success, NSError *error) {
            dispatch_async(dispatch_get_main_queue(), ^{
                NSLog(@"Verify successful");
            });
        }];
    });
}
@end

iPhone 6s

iOS 13-beta6

iOS 13-bata1 same behavior

iOS 13-beta5 same behavior