CORS error for one route in Angular/Laravel on one server but not another

I fear this may be flagged as a duplicate of my own question but I have honestly exhuasted everything , even from that question...

The problem:

I am making a get request to my Laravel API and getting the following error

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at http://www.example.com/exceptions-company-reports. (Reason: CORS header 'Access-Control-Allow-Origin' missing)

Note, this error only appears for this particular request. Not the other ones below. However I did try make a new one and got the same error despite everything else continuing to work on the application

I cannot define what is happening and why that particular request does not work and others do.

Things to note:

• Everyting is working fine on my local vagrant server, replica code
• All other requests are working fine, even to that controller
• The routes are appearing correctly when I run php artisan route:list
• I have run composer update both on local and this server
• My error logs are showing no php/syntax errors, but errors are working as they do show up when there actually is an error
• I have stripped all the code below to have bare functions and I am still getting the same problem. this includes removing the likes of Excel, stripping other potential problem causing functions. And besides, the lack of PHP errors should indicate that is not the cause anyway.
• AngularJS v1.6.2 and Laravel 5.4.16

Client side Angular code (the middle function is the one giving me the CORS error), the other two work perfectly:

getMainEirReports: function getMainEirReports() {
    var apiBase = apiUrl + 'main-eir-reports';
    var config = {
    //responseType: 'blob'
    };
    return $http.get(apiBase, config);
},
getExceptionsReport: function getExceptionsReport() {
    var apiBase = apiUrl + 'exceptions-company-reports';
    var config = {
        responseType: 'blob'
    };
    return $http.get(apiBase, config);
},
getExceptionsReportList: function getExceptionsReport() {
    var apiBase = apiUrl + 'exceptions-company-reports-list';
    var config = { };
    return $http.get(apiBase, config);
}

Server Side (routes/web.php)

Route::group([ 'middleware' => 'cors'], function()
{
// Company Reporting
Route::get('main-company-reports', 'CompanyreportingController@mainCompanyReports');
Route::get('exceptions-company-reports', 'CompanyreportingController@exceptionsCompanyReports');
Route::get('exceptions-company-reports-list', 'CompanyreportingController@exceptionsCompanyReportsList');
});

Server side (CompanyreportingController.php):

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\Http\Requests\PublishCompanyreportingRequest;
use DB;
use Auth;
use Excel;



class CompanyreportingController extends Controller {

    public function __construct() {
        $this->middleware( 'jwt.auth' );
        $this->middleware( 'role:company-reports' );

    }

    public function mainCompanyReports( PublishCompanyreportingRequest $requestData ) {
        $mainReports = DB::table( 'main_reports' )->select('label_id','tracking_number','unit_status')->get();
        return response()->json( $mainReports );
    }




    public function exceptionsCompanyReports( PublishCompanyreportingRequest $requestData ) {

        $list = DB::table( 'exceptions_reports' )->select('created_at','account_number','customer_name','fp','seriel_number','comment','grade','item_number','description')->get();
        $rows = array();
        foreach($list as $item) {
            $rows[] = array(
                "Received" => $item->created_at,
                "Account Number"=> $item->account_number,
                "Customer Name" => $item->customer_name,
                "FP"=> $item->fp,
                "Serial Number" => $item->seriel_number,
                "Comment" => $item->comment,
                "Grade" => $item->grade,
                "Item Number" => $item->item_number,
                "Description" => $item->description,
            );
        }

        Excel::create('Filename2', function($excel) use($rows) {

            // Set the title
            $excel->setTitle('Iqutech | Company Exceptions Report');

            // Chain the setters
            $excel->setCreator('Iqutech')
                  ->setCompany('Iqutech');
            $excel->sheet('Exceptions Report', function($sheet) use($rows) {

                $sheet->fromArray($rows);
                $sheet->row(1, function($row) {

                    // call cell manipulation methods
                    $row->setBackground('#DDDDDD');
                    $row->setFontFamily('Calibri');
                    $row->setFontSize(14);

                });
                $sheet->setStyle(array(
                    'font' => array(
                        'name'      =>  'Calibri',
                        'size'      =>  14
                    )
                ));

            });
            // Call them separately
            $excel->setDescription('A demonstration to change the file properties');

        })->download('xlsx');
    }

    public function exceptionsCompanyReportsList( PublishCompanyreportingRequest $requestData ) {

        $list = DB::table( 'exceptions_reports' )->select('created_at','account_number','customer_name','fp','seriel_number','comment','grade','item_number','description')->get();
        return response()->json( $list );
    }

}

Routes:

|        | GET|HEAD  | exceptions-company-reports                            |                            | App\Http\Controllers\CompanyreportingController@exceptionsCompanyReports                  | web,cors,jwt.auth,role:company-reports        |
|        | GET|HEAD  | exceptions-company-reports-list                       |                            | App\Http\Controllers\CompanyreportingController@exceptionsCompanyReportsList              | web,cors,jwt.auth,role:company-reports        |
|        | GET|HEAD  | main-company-reports                                  |                            | App\Http\Controllers\CompanyreportingController@mainCompanyReports                        | web,cors,jwt.auth,role:company-reports        |

via Adrian