flowchart RL
    %% OK
    A[$$x$$]

    %% OK
    B["$$x$$"]

    %% OK
    C@{ shape: rect, label: $$x$$}  

    %% OK
    D@{ shape: rect, label: "$$x$$"}  

    %% OK
    E[$$\sin x$$]

    %% OK
    F["$$\sin x$$"]
    
    %% OK
    G@{ shape: rect, label: $$\sin x$$}  

    %% bug
    H@{ shape: rect, label: "$$\sin x$$"}