Why is my Progress HUD not displaying as expected - objective-c

Question

I'm trying to develop a 'passwordless' registration form using a QRCode. The background processing works (can authenticate user), but noting happens visually until the registration is complete and the user is redirected to the apps main ViewController, however, A progress dialog with spinner is supposed to appear during the registration process but it doesn't. If, I manually input the credentials and press 'authenticate', everything works as expected, Just not after scanning the QR code.
Please see code below:
#interface ViewControllerRegister (){
JGProgressHUD *HUD;
NSString *regid;
NSString *regpin;
NSMutableDictionary *dicto;
}
//OPEN QRCODE READER VC
- (IBAction)scanAction:(id)sender
{
if ([QRCodeReader supportsMetadataObjectTypes:#[AVMetadataObjectTypeQRCode]]) {
static QRCodeReaderViewController *vc = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
QRCodeReader *reader = [QRCodeReader readerWithMetadataObjectTypes:#[AVMetadataObjectTypeQRCode]];
vc = [QRCodeReaderViewController readerWithCancelButtonTitle:#"Cancel" codeReader:reader startScanningAtLoad:YES];
vc.modalPresentationStyle = UIModalPresentationFormSheet;
});
vc.delegate = self;
[vc setCompletionWithBlock:^(NSString *resultAsString) {
// NSLog(#"Completion with result: %#", resultAsString);
}];
[self presentViewController:vc animated:YES completion:NULL];
}
else {
[self showAlert:#"Reader not supported by the current device"];
}
}
//// PARSE THE RETURNED QR CODE DATA
#pragma mark - QRCodeReader Delegate Methods
- (void)reader:(QRCodeReaderViewController *)reader didScanResult:(NSString *)result
{
[self dismissViewControllerAnimated:YES completion:^{
NSURL *stringfromscan = [NSURL URLWithString:result];
dicto = [NSMutableDictionary new];
NSURLComponents *components = [NSURLComponents componentsWithURL:stringfromscan resolvingAgainstBaseURL:NO];
NSArray *queryItems = [components queryItems];
for (NSURLQueryItem *item in queryItems)
{
[dicto setObject:[item value] forKey:[item name]];
}
if ([result rangeOfString:#"eloq"].location == NSNotFound && [result rangeOfString:#"unique"].location == NSNotFound) {
[self showAlert:#"Looks like you've scanned an incorect QR code"];
} else {
self.TextViewUniqueID.text = [dicto objectForKey:#"uniqueid"];
self.TextViewPIN.text = [dicto objectForKey:#"password"];
double delayInSeconds = 1.0;
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
[self authent];
});
}
}];
}
/// CREDENTIAL VALIDATION OF SORTS
- (void)authent{
NSLog(#"s UNIQUEID %#", self.TextViewUniqueID.text);
NSLog(#"PIN %#", self.TextViewPIN.text);
// [self resignFirstResponder];
int uniqueID = [self.TextViewUniqueID.text length];
int PIN = [self.TextViewPIN.text length];
if (uniqueID < 7 || PIN < 6){
UIAlertController* alert = [UIAlertController alertControllerWithTitle:#"Error!"
message:#"Your UniqueID or PIN is too short."
preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction* defaultAction = [UIAlertAction actionWithTitle:#"Try Again" style:UIAlertActionStyleDefault
handler:^(UIAlertAction * action) {}];
[alert addAction:defaultAction];
[self presentViewController:alert animated:YES completion:nil];
[self clear];
}else{
/*
HUD WILL NOT DISPLAY AFTER READING QR CODE
*/
HUD = [JGProgressHUD progressHUDWithStyle:JGProgressHUDStyleDark];
HUD.textLabel.text = #"Authenticating";
[HUD showInView:self.view];
[self PostJson:self.TextViewUniqueID.text :self.TextViewPIN.text];
}
}