Is it possible to do the diagram I am trying to do (U-shape)?

[gomi92]

I can't figure out how to create this shape. Everything I try leads to it becoming strictly horizontal/vertical, which is not what I want.

flowchart TB
    subgraph SendingMachine
        direction TB
        A[user application]
        A --> B[network software]
        B --> C[network protocol]
        C --> D[network interface]
    end
    
    subgraph ReceivingMachine
        direction BT
        F[network interface]
        F --> G[network protocol]
        G --> H[network software]
        H --> I[user application]
    end

    subgraph X
        E[network medium]
    end

    SendingMachine --> D ---> X --> F --> ReceivingMachine

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flowchart LR
    subgraph SendingMachine
        direction TB
        A[user application]
        A --> B[network software]
        B --> C[network protocol]
        C --> D[network interface]
    end
    
    subgraph ReceivingMachine
        direction BT
        F[network interface]
        F --> G[network protocol]
        G --> H[network software]
        H --> I[user application]
    end

    subgraph X
        E[network medium]
    end

    SendingMachine --> D ---> X --> F --> ReceivingMachine

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flowchart LR
    subgraph SendingMachine
        direction TB
        A[user application]
        A --> B[network software]
        B --> C[network protocol]
        C --> D[network interface]
    end
    
    subgraph ReceivingMachine
        direction BT
        F[network interface]
        F --> G[network protocol]
        G --> H[network software]
        H --> I[user application]
    end

    subgraph X
        E[network medium]
    end

    SendingMachine --> X --> ReceivingMachine

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