Laravel one to one polymorphic relationship returns null

I'm facing issue in one to one polymorphic relationship in laravel 6.0.

I have 2 Model CategoryModel and SeoModel(Polymorphic model with one to one relationship)

Below is a snippet from controller where i try to add category and its seo's.

        $info=[];
        $query = [
            'name' => 'name',
            'description' => 'description',
            'parent_id' => NULL,
            'status' => 1,
            'image' => NULL,
            'sort_order' => 1,
        ];
        // dd($query);

        $info["category"]= new CategoryModel;
        $info["seo"] = new SeoModel;

        $info['category']->fill($query);
        $info['category']->save();

        $seo_query = [
            'meta_title' => 'meta_title',
            'meta_description' => 'meta_description',
            'meta_keyword' => 'meta_keyword',
            'seoable_id' => $info['category']->getKey(),
            'seoable_type' => CategoryModel::class,
        ];

        // dd($seo_query);

        $info['category']->seo()->create($seo_query);
        $info['category_id']= $info['category']->getKey();

        return $info;

SeoModel Path : App/Models/Seo/SeoModel

class SeoModel extends Model
{
    use SoftDeletes, ModelTrait;

    protected $table = 'seo';
    protected $primaryKey = 'id';
    protected $fillable = ['meta_title', 'meta_description', 'meta_keyword', 'seoable_id', 'seoable_type'];
    protected $dates = ['deleted_at'];
    public $incrementing = false;

    public function seoable()
    {
        return $this->morphTo();
    }

}

CategoryModel Path : App/Models/Category/CategoryModel

namespace App\Models\Category;

use App\Models\Seo\SeoModel;
use App\Traits\ModelTrait;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\SoftDeletes;
use Illuminate\Support\Facades\Log;

class CategoryModel extends Model
{
    use SoftDeletes, ModelTrait;

    protected $table = 'category';
    protected $primaryKey = 'category_id';
    protected $fillable = ['name', 'description', 'parent_id', 'status', 'image', 'sort_order'];
    protected $dates = ['deleted_at'];
    protected $with = ['seo'];

    protected $appends = ['image_url'];
    protected $file_directory = "categories/";

    public function getImageUrlAttribute() {
        return $this->resolveFileUrl($this->attributes['image']);
    }

    public function seo(){
        return $this->morphOne(SeoModel::class, 'seoable');
    }
}

Thanks in Advance

via Chebli Mohamed