Type of Eloquent model's morphOne relationship cant be inferred in HyperF

[Hanmo123]

I am using HyperF and its ORM is based on Eloquent.

This is my model definition:

class CpsInstance extends AbstractProductInstance implements HourlyPostPaidProductInstance
{
    public function instance()
    {
        return $this->morphOne(Instance::class, 'product_instance', 'product_class', 'id');
    }
}

and access instance in service

$instance = $productInstance->instance;

it shows:

while other non-morphOne relationships are normal but are mixed type(is there a way to infer correctly in hyperf?)