Communism

So I’m new to everything. Curious about Anarchism and Communism. What I’m finding is that Anarchists and Communists seem to not get along and dislike each other. I can understand that Communism’s progression requires hierarchy of a sort as is moves from Capitalism to Socialism to actual Communism. But the end goal seems the same. Classless, Stateless, moneyless society. What is the deal with this antagonism? Communists think Anarchists have no plan and it seems Anarchists find communists kinda fascist. Is that the issue? I’m under this idea that Nom Chomsky talked about where if a person is in an authority position, they need to be able to prove their need to be there. So that idea led me to believe that Anarchists aren’t against authority of all kinds or organizing. So couldn’t that idea be put into place within the Socialism section of the plan to move to communism?

Thanks all!