Laravel Auditing Not Logging old_values and new_values When Using Observer

I’m working with Laravel Filament where I’m using audits package for audits the activity of laravel model. I’ve laravel model like:

<?php

namespace AppModels;

use AppCastsMoney;
use AppObserversInventoryObserver;
use IlluminateDatabaseEloquentAttributesObservedBy;
use IlluminateDatabaseEloquentBuilder;
use IlluminateDatabaseEloquentFactoriesHasFactory;
use IlluminateDatabaseEloquentModel;
use IlluminateDatabaseEloquentRelationsBelongsTo;
use IlluminateDatabaseEloquentRelationsHasOne;
use IlluminateDatabaseEloquentSoftDeletes;
use OwenItAuditingContractsAuditable;

#[ObservedBy(InventoryObserver::class)]
class Inventory extends Model implements Auditable
{
    use OwenItAuditingAuditable;
    use HasFactory, SoftDeletes;

    protected $guarded = [];
}

And InventoryObserver.php

<?php

namespace AppObservers;

use AppEventsRefreshInventories;
use AppEventsRefreshProducts;
use AppModelsInventory;
use AppServicesTaxCalculatorService;

class InventoryObserver
{
   public function created(Inventory $inventory): void
    {
        if ($inventory->gross_amount) {
            $taxCalculatorService = TaxCalculatorService::make($inventory->gross_amount, $inventory->tax_rate);

            $inventory->net_amount = $taxCalculatorService->getNetAmount();
            $inventory->tax_amount = $taxCalculatorService->getTaxAmount();

            $inventory->saveQuietly();
        }

        $inventory->machine->updateStockPercentage();
    }

    public function updated(Inventory $inventory): void
    {
        if ($inventory->isDirty(['gross_amount', 'tax_rate'])) {
            $taxCalculatorService = TaxCalculatorService::make($inventory->gross_amount, $inventory->tax_rate);

            $inventory->net_amount = $taxCalculatorService->getNetAmount();
            $inventory->tax_amount = $taxCalculatorService->getTaxAmount();

            $inventory->saveQuietly();

            //            RefreshProducts::broadcast($inventory->machine);
        }

        if ($inventory->isDirty('quantity', 'max_quantity')) {
            $inventory->machine->updateStockPercentage();

            //            RefreshInventories::broadcast($inventory->machine);
        }
    }

When I’m saving values from form it’s auditing the values in audits database table with empty values inside old_values and new_values.

Can anyone help me how can I solve this problem?

Thanks…