Cashier kills script when creating StripeCustomer?

I'm using Cashier on a new site that takes a single charge to a user when they place a booking

Stripe has been working without a problem for the last several weeks while it's been in development, until a few of days ago when this issue seemingly popped up out of nowhere

When trying to complete the payment via the iframe, Chrome started returning the following error when calling the endpoint - (failed)net::ERR_EMPTY_RESPONSE

Inside my controller function, I narrowed it down to this line being the issue

$user->createOrGetStripeCustomer()

My $user Model is being set correctly so I knew the issue was inside the createOrGetStripeCustomer function

I looked inside the Cashier src and I found it to be this line that's causing the issue;

// Laravel\Cashier\Concerns\ManagesCustomer

$customer = $this->stripe()->customers->create($options);

stripe(), customers and $options are all being set correctly so something appears to be going wrong when it tries to create this Model

Is there something I'm missing that could be causing this issue? I updated all my packages and following the migration guide for Cashier as I was previously on v12, but the issue persists

Here's my User Model;

CREATE TABLE `users` (
  `id` int unsigned NOT NULL AUTO_INCREMENT,
  `first_name` varchar(191) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
  `last_name` varchar(191) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
  `email` varchar(191) COLLATE utf8mb4_unicode_ci NOT NULL,
  `phone` varchar(191) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
  `email_verified_at` timestamp NULL DEFAULT NULL,
  `password` varchar(191) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
  `enabled` tinyint(1) NOT NULL,
  `remember_token` varchar(100) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
  `last_login` timestamp NULL DEFAULT NULL,
  `created_at` timestamp NULL DEFAULT NULL,
  `updated_at` timestamp NULL DEFAULT NULL,
  `deleted_at` timestamp NULL DEFAULT NULL,
  `stripe_id` varchar(191) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
  `pm_type` varchar(191) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
  `pm_last_four` varchar(4) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
  `trial_ends_at` timestamp NULL DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `users_email_unique` (`email`),
  KEY `users_stripe_id_index` (`stripe_id`)
) ENGINE=InnoDB AUTO_INCREMENT=7225 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

Any help with this would be greatly appreciated, I've been scratching my head at this for 3 days now