eloquent illuminate create method does not work

For some reason, I cannot create models on this page. It has always worked until today.

What I have done

1. I also tested var_dump after and before OrderDetails::create() and both value are the same.
2. I messed around with $fillable and it is clear that when column name inside of fillable are not matched database column. Error will be shown.
3. I tried all variation of of create method, and still no luck.

I have absolutely no clue what I did wrong here.

additional information: 1. I messed around with phpMailer before I detected this error. One major thing i did is to turn on "allow less secure access" (not exact word) which convert from "ssl" to "tsl."

Below is one of the models I cannot create. I chose to show part of the code that most relevant to my problem.

foreach($_SESSION['user_cart'] as $cart_items){

                $productId = $cart_items['product_id'];

            //quantity of items in the cart NOT quatity of item availble in the shop
                $quantity = $cart_items['quantity'];

                $item = Product::where('id', $productId)->first();

            //if for some reason, no matching id can be found. skip the item to avoid problems
                if(!$item) {continue;}
            //totalPrice of selected item * quantity in the cart
                $totalPrice = $item->price * $quantity;
                $totalPrice = number_format($totalPrice, 2 );

                // var_dump($order_id); //?????????????????????????????????????????????????????????????

                OrderDetail::create([
                    'user_id' => _user()->id,
                    'product_id' => $productId,
                    'unit_price' => $item->price,
                    'quantity' => $quantity,
                    'total' => $totalPrice,
                    'status' => 'Pending',
                    'order_no' => $order_id
                ]);
                $item->quantity = $item->quantity - $quantity;
                $item->save();

                // $test = OrderDetail::where("order_no", $order_id)->get();
                // var_dump($test[0]->order_no); //?????????????????????????????????????????????????????

                array_push($result['product'], [
                    'name' => $item->name,
                    'price' => $item->price,
                    'total' => $totalPrice,
                    'quantity' => $

This is my OrderDetail model

namespace SAM\Models;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\SoftDeletes;

class OrderDetail extends Model
{
    //Illuminate setup6
    use SoftDeletes;
    public $timestamps = true;
    // vars to be inserted to
    protected $fillable = ['user_id', 'product_id', 'unit-price', 'quantity', 'total', 'status', 'order_no'];
    // protected $fillable = ['user_id', 'product_id', 'unit-price', 'quantity', 'total', 'statu_no'];
    protected $dates = ['deleted_at'];
}

via Chebli Mohamed