Flurry iOS test Push Notification fails with UnrecognizedDeviceId

Question

Trying to integrate the Flurry Push Notification service on iOS. When testing the integration I am getting

Unable to send test push. Reason: UnrecognizedDeviceId. See troubleshooting documentation.

I am using the IDFA/IDFV

Things I have already verified:

• The Apple Push Sandbox SSL certificate is valid
• I am using correct FLurry API key
• User has granted all the notification permissions
• Looked at the Test Push Troubleshooting, and UnrecognizedDeviceId. Nothing useful there!
• Make sure the IDFA/IDFV is correct

I have done a complete setup following these guides:

1. Flurry Push for iOS
2. Push Authorization

The last step involves Test Push.

Here is the code I'm using to registered Flurry in my app

#include "Flurry.h"
#include "FlurryMessaging.h"

:
:
:
- (BOOL) application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
  [FlurryMessaging setAutoIntegrationForMessaging];
  [FlurryMessaging setMessagingDelegate:self];

  FlurrySessionBuilder* builder = [[FlurrySessionBuilder alloc] withIncludeBackgroundSessionsInMetrics:YES];
  [builder withLogLevel:FlurryLogLevelAll];
  [Flurry startSession:@"XXXXXX" withOptions:launchOptions withSessionBuilder:builder];
}

// To make sure iOS is registering notifications I added this override and it is being called with non-null deviceToken
- (void)application:(UIApplication *)app didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)deviceToken
{
  NSString* tokenString = [deviceToken base64EncodedStringWithOptions:NSDataBase64EncodingEndLineWithLineFeed];

  NSLog(@"The generated device token string is : %@",tokenString);
}

Device Info: iPhone7 Plus iOS: 13.3.1

Any help appreciated!

Update 1

Tried setting the deviceToken in Flurry but still the same error.

- (void)application:(UIApplication *)app didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)deviceToken
{
  [FlurryMessaging setDeviceToken:deviceToken];
}