API Posts in Production not working

I'm pretty stumped so if anyone can point me in a direction I'd really appreciate it.

Everything is working 100% correctly on my local dev machine (Mac). Now when I deploy to a production server my Post requests don't work. I am testing requests via POSTMAN.

1. GET requests work in dev and production
2. GET requests know if auth code is valid in dev and production
3. POST to "rewards" route result in 500 internal server errors in production (dev works)
4. POST to "test" route result in 404 Method Not Allowed in production (dev works)

/routes/api.php

Route::prefix('v1')->group(function () {
    Route::middleware('auth:api')->group( function () {
        Route::apiResource('rewards', 'API\RewardTransferController');
        Route::apiResource('rewards/customers', 'API\CustomerController');
        Route::get('rewards/customers/bri/{briCustomerNumber}', 'API\CustomerController@getByBriCustomerNumber')->where('briCustomerNumber', '[0-9]{7}');
        Route::post('test', function()
        {
            return "POST SUCCESS!";
        });
    });
});

In the above my /rewards/customers/bri/{briCustomerNumber} route does work in dev and in production.

However, my "test" route does not work in production. The response is json response like this:

{
    "message": ""
}

Additionally a POST request to "rewards" results in an empty response... no JSON format and it is 500 Internal Error.

Anyone know something I can look into to figure out why things aren't working on my production server? My GUI backend works 100% correctly but the test API with POSTMAN doesn't work on POST requests.