IEEEproof: Proof name not respected

[nschloe]

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\documentclass{IEEEtran}
\begin{document}
\begin{IEEEproof}[Proof of Pythagoras]
abc.
\end{IEEEproof}
\end{document}

LaTeX output:

Proof of Pythagoras: abc. ∎

LaTeXML output:

  <proof>
    <title class="ltx_runin" font="bold italic">Proof:</title>
    <para xml:id="p1">
      <p>abc.
∎</p>
    </para>
  </proof>

The name Proof of Pythagoras is lost.

Also, the LaTeX font isn't "bold italic".