AWS IOS DynamoDB Scan SDK - Scan thread works on the emulator, but not when debugging on the device

In my app I use a scan with DynamoDB that works perfectly in the emulator for all versions of iOS that xCode provides, however, when debugging on the device (iPhone 5c), it does not run the main thread.

[[[dynamoDBObjectMapper scan:[DDBTableRow class]
                  expression:scanExpression]
      continueWithExecutor:[BFExecutor mainThreadExecutor] withSuccessBlock:^id(BFTask *task) {
//Execução da Thread principal          
.
.
.
return nil;
  }] continueWithExecutor:[BFExecutor mainThreadExecutor] withBlock:^id(BFTask *task) {
      if (task.error) {
          NSLog(@"refreshList Error");
      }
      return nil;
  }];

Any ideas?