Fixtures are not populated with _id on load.

[Lisio]

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