Laravel - why a 419 response when request size is too large?

When we make a request to our database with a nine hundred or more IDs in the request body we are hit with a 419 | Page Expired response. However when we make the same request with 800 or fewer IDs the request executes successfully. Why would a large request size throw a 419 error?

On the frontend we add IDs to the request and the request object looks like this:

class MyCustomRequest extends FormRequest
{
    public function authorize(): bool
    {
        return true;
    }

    public function rules(): array
    {
        return [
            'object_ids'   => 'required|array|min:1',
            'object_ids.*' => 'required|integer',
        ];
    }
}

I don't think it has to do with our session_lifetime is defaulted to 24 hours. The 419 response comes back pretty quickly too:

'lifetime' => env('SESSION_LIFETIME', 86400),

Any idea why we are getting 419 response when there are 900 or more object_ids present in the request?

via Chebli Mohamed