Text Formatting ⇒ Greek math letters are not printed in the list of todo notes

[user49915]

Feeding

\documentclass{article}
\pagestyle{empty}
\usepackage[math-style=ISO]{unicode-math}
\setmainfont[Ligatures=TeX]{TeX Gyre Termes}
\setsansfont{TeX Gyre Heros}[Scale=0.88]
\setmonofont{TeX Gyre Cursor}
\setmathfont[Ligatures=TeX]{TeX Gyre Termes Math}
\usepackage{todonotes}
%%% Simplified http://tex.stackexchange.com/a/549106 :
\ExplSyntaxOn
\NewDocumentCommand{\myMacro}{m}{
\tl_set:Nn \l_tmpa_tl { #1 }
\regex_replace_all:NnN
\c_justaman_mymacro_greek_regex % search
{ \c{symit}\cB\{\1\cE\} } % replace
\l_tmpa_tl % token list to massage
\mathit{\tl_use:N \l_tmpa_tl}
}
\regex_const:Nn \c_justaman_mymacro_greek_regex
{% one or more Greek letters; fill up
([\c{alpha}\c{beta}\c{gamma}]+)
}
\ExplSyntaxOff
\begin{document}
\listoftodos
\clearpage
\noindent\(\myMacro{\alpha}\)\\
\(\myMacro{Finite\_word\_with\_\alpha}\)
\todo[inline]{\(\myMacro{\alpha}\)\\
\(\myMacro{Finite\_word\_with\_\alpha}\)}
\end{document}

to xelatex results in the following second page, which is o.k.:

page 2

p2.png (5.68 KiB) Viewed 1853 times

But in the list of todo notes on the first page, the \alphas are missing:

p1.png (4.67 KiB) Viewed 1853 times

Any idea of what goes on here and how to repair this bug? Crosspost: http://github.com/henrikmidtiby/todonotes/issues/47.