The Star Trek universe is not communist, although it is often misunderstood as such. Here are some arguments against it:
Private property exists: Characters in Star Trek own personal items like clothes, PADDs (Personal Access Display Devices), and other belongings. This contradicts the communist ideal of common ownership of the means of production.
Currency exists: Although the Federation claims to be a post-scarcity society, there is evidence of some form of currency, such as "credits" or "gold-pressed latinum," which are used for trade with other civilizations.
Social hierarchies exist: In Star Trek, there are clear social hierarchies, such as ranks in Starfleet, different positions in government, and various social classes. This contradicts the communist idea of a classless society.
Individual freedom is valued: Characters in Star Trek have the freedom to make their own choices, pursue their own careers, and hold their own beliefs. This contrasts with the communist idea of collectivism, where the individual is subordinate to the good of the community.
Replicators do not create abundance: Although replicators can produce many goods, they cannot replicate everything, such as latinum or complex technologies. This means that there is still scarcity, and resources are not unlimited.
Competition and rivalry exist: In Star Trek, there is evidence of competition and rivalry, for example in scientific discoveries, sporting events, or political debates. This contradicts the communist idea of cooperation and shared progress.
The Federation is a democratic republic: The Federation is depicted as a democratic republic, where citizens elect their representatives and participate in political decision-making. This is fundamentally different from communist systems, which are often one-party states with limited political freedom.
Although Star Trek presents an idealized vision of the future where many social problems have been solved, it is important to emphasize that it is not a communist society. There are many elements in Star Trek that contradict the basic principles of communism.
I've seen someone make the distinction on here where private property is factories means of productions and such and personal property is the stuff you own including things like your home