TikZ-Feynman does not print the "crossed dot". What is the right syntax?

Question

I am using the package tikz-feynman to draw feynman diagrams with latex. I would like to reproduce the following diagram

Reading the user manual of the package tikzfeynman, one discovers that to draw the current insertion in the vertex it is sufficient to use the label "crossed dot". Indeed, if one uses it in the \feynmandiagram{ *here* } construct, it works just fine. However, personally I had few difficulties in representing this clean layered structure. Therefore, I used the following code

\begin{tikzpicture}
        \begin{feynman}
        \vertex (i) {\(h_\lambda\)};
        \vertex[right=1cm of i, crossed dot] (a);
        \vertex[right=2cm of a] (b);
        \vertex[right=1cm of b] (f) {\(h_\sigma\)};
        \vertex[below=1cm of a] (s1);
        \vertex[left=.5cm of s1] (s11);
        \vertex[right=.5cm of s1] (s12);
        \vertex[below=1cm of b] (s2);
        \vertex[left=.5cm of s2] (s21);
        \vertex[right=.5cm of s2] (s22);
        
        \diagram*{
            (i) -- [boson] (a)
            -- [boson, thick, momentum=\(\vec{p}\)] (b)
            -- [boson] (f),
            (s11) -- [scalar, insertion=0] (a) -- [scalar, insertion=1] (s12),
            (s21) -- [scalar, insertion=0] (b) -- [scalar, insertion=1] (s22),
        };
        \end{feynman}
\end{tikzpicture}

which produced the output

I tried in many ways to introduce the [crossed dot] tag but it appears that the diagram* does not accept it, despite compilation runs just fine. For instance, I tried \vertex[right=1cm of i, crossed dot] as well as i -- [boson] (a) [crossed dot] without success.

• Have you any clues of why this tag does not work in this code? Do you have any suggestion?
• Is is possible to define a vertex "above and left"? If yes, what is the syntax?

Thank you

Answer 1

Instead of vertex use node -- this is a bug as defined here --https://tex.stackexchange.com/a/532652/197451

\begin{tikzpicture}
    \begin{feynman}
    \vertex (i) {\(h_\lambda\)};
    \node[right=1cm of i, crossed dot] (a);%<--------------------amend to node
    \vertex[right=2cm of a] (b);
    \vertex[right=1cm of b] (f) {\(h_\sigma\)};
    \vertex[below=1cm of a] (s1);
    \vertex[left=.5cm of s1] (s11);
    \vertex[right=.5cm of s1] (s12);
    \vertex[below=1cm of b] (s2);
    \vertex[left=.5cm of s2] (s21);
    \vertex[right=.5cm of s2] (s22);
    
    \diagram*{
        (i) -- [boson] (a)
        -- [boson, thick, momentum=\(\vec{p}\)] (b)
        -- [boson] (f),
        (s11) -- [scalar, insertion=0] (a) -- [scalar, insertion=1] (s12),
        (s21) -- [scalar, insertion=0] (b) -- [scalar, insertion=1] (s22),
    };
    \end{feynman}
    \end{tikzpicture}