PhpStorm can not auto-completion Symfony Doctrine field name on repository file?

PhpStorm version is 2020.1

1. I use composer create-project symfony/website-skeleton . to create new app
2. Use php bin/console make:entity make new entity
3. make:migration and doctrine:migrations:migrate to make database table
4. In Repository.php file, the createQueryBuilder('a')->andWhere('a.can not auto-completion')

I have installed Symfony plugin for PhpStorm.

Why and how to fix it?