My subscription mutation in server duplicate another node in clients

[ioofy]

Hello, everyone
I have some issue in apollo client with subscription
if I do mutation in server and i want to see in client it was duplicate
it this problem with apollo client? or am i miss something

i want my query and subscription is updating every any subscription come.

duplicate in the bottom

my apollo cache.ts

import { InMemoryCache } from "@apollo/client";
import { offsetLimitPagination } from "@apollo/client/utilities";

export const cache = new InMemoryCache({
  typePolicies: {
    Query: {
      fields: {
        posts: offsetLimitPagination(),
        comments: {
          keyArgs: false,
          merge(existing: [], incoming) {
            return incoming;
          },
        },
      },
    },
  },
});

index.ts indicate duplicate node

const GET_NEW_POST_SUBS = gql`
  subscription postCreated {
    postCreated {
      id
      content
      createdAt
      user {
        avatarUrl
        username
        id
        name
      }
      likes {
        user {
          avatarUrl
          name
        }
        id
      }
      comments {
        id
        user {
          avatarUrl
          name
          username
        }
      }
    }
  }
`;

const Post = () => {
  const [fullyLoaded, setFullyLoaded] = useState<any>(false);
  const { data, networkStatus, error, fetchMore, variables, subscribeToMore } =
    usePostQuery({
      variables: {
        limit: 5,
        offset: 0,
      },
      fetchPolicy: "network-only",
      notifyOnNetworkStatusChange: true,
    });

  useEffect(() => {
    subscribeToMore({
      document: GET_NEW_POST_SUBS,
      // not using use subscription with graphql codegen
      updateQuery: (prev: any, { subscriptionData }: any) => {
        if (!subscriptionData.data) return prev;
        const newPost = subscriptionData.data.postCreated;

        return {
          posts: [...prev.posts, newPost],
        };
      },
    });

    console.log(posts?.length);
  });

Please help…