Миграция Laravel: errno: 150 «Ограничение внешнего ключа сформировано неправильно»

я получаю сообщение об ошибке

SQLSTATE[HY000]: General error: 1005 Can't create tableposys.#sql-2b94_d2(errno: 150 "Foreign key constraint is incorrectly formed") (SQL: alter tableпокупка_заказовadd constraint Purchase_orders_status_id_foreignforeign key (status_id) referencesстатусы(id))

При запуске моей миграции.

Вот мои миграции:

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateStaffTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('staff', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->string('name')->unique();
            $table->string('position')->nullable();
            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('staff');
    }
}

А также

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreatePurchaseOrdersTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('purchase_orders', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->float('total_price_ex_vat', 12, 2);
            $table->float('total_price_inc_vat', 12, 2);
            $table->string('deliver_to'); 
            $table->unsignedBigInteger('staff_id'); // Foreign key
            $table->foreign('staff_id')->references('id')->on('staff');
            $table->unsignedBigInteger('supplier_id'); // Foreign key
            $table->foreign('supplier_id')->references('id')->on('suppliers');
            $table->unsignedBigInteger('status_id'); // Foreign key
            $table->foreign('status_id')->references('id')->on('statuses');
            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('purchase_orders');
    }
}