The recurring issue with communism is that capitalist powers keep on trying to corrupt, infiltrate and sabotage popular governments.

Idk, while capitalism meddling in communist governments is a reoccurring theme, I think blaming all problems that have occurred within communist governments on any level of outside corruption is highly reductive.

The problem with Marx is that while it points out problems and offers some solutions, it doesn't address the way to organize a governmental hierarchy. Specifically it does not outline the required path of transforming a revolutionary government into a functional communist government.

Revolutions require a very rigid hierarchy of control and command, and most often resembles a military command structure rather than a bureaucratic one. Transitioning the state control from the hands of revolutionary militants to bureaucratic policy makers is the pitfall of any revolution, Marxist or not.