Problem with foreach - array offset on null

Hi,

I've a problem, in my component I've 2 methods :

#[Computed]
    public function resourceTypes()
    {
        return ResourceTypeModel::orderBy('name', 'ASC')->get();
    }

    #[Computed]
    public function periodicityTypes()
    {
        return PeriodicityTypeModel::orderByRaw("FIELD(reference, 'mensuelle', 'trimestrielle', 'semestrielle', 'annuelle') DESC")->get();
    }

In my blade template, I try to use foreach, it doesn't work

<flux:select variant="listbox" placeholder="Choose industry...">
	@foreach($this->resourceTypes as $item)
		<flux:select.option>{{ $item->name }}</flux:select.option>
	@endforeach
</flux:select>

I've this error

Trying to access array offset on null (View: /var/www/vendor/laravel/framework/src/Illuminate/Foundation/resources/exceptions/renderer/markdown.blade.php)

If I change resourceTypes by resources in my blade template IT WORKS, I don't what's wrong with resourceTypes !!! If anybody can help ?