Fixtures are not populated with _id on load. ### What steps will reproduce the problem? $user = $I->grabFixture('users', 'user1'); ### What's expected? Fixture is found ### What do you get instead? Fixture not found. ### Additional info | Q | A | ---------------------- | --- | Yii version | 2.0.35 | Yii MongoDB version | 2.1.9 | MongoDB server version | 4.2.6 | PHP version | 7.4.6 | Operating system | Ubuntu 20.04