“Not real communism” has 2 flavors.

1. Western “leftist” edition, claiming all existing socialist states never achieved even socialism

2. Marxist edition, pointing out that socialism is a transition to communism, and that communism has not been achieved yet.

The latter is correct, but often gets mistaken for the former, which results in rhetorical gotchas by liberal debatelords.

Lysenkoism vs Corporatism.