# Unicode-math and mathrm result in missing symbols

I've played around for a while and searched quite a bit but can't find a solution. my code is the following

\documentclass{article}
\usepackage{hepnicenames}
\usepackage{fontspec}
\usepackage[math-style=ISO]{unicode-math}

\setmathfont{Latin Modern Math}
\setmainfont{Latin Modern Roman}

\begin{document}

$$\mu + \mathrm{\mu} - γ + \mathrm{γ} + \Pmuon$$
\end{document}


Unfortunately, when compiling with luatex the mathrm versions never get printed but are simply missing.

• Welcome to the site. I can confirm the behavior with my installation. – Steven B. Segletes May 8 at 18:00

\mathrm is the wrong command, use \symrm

\documentclass{article}
\usepackage{hepnicenames}
\usepackage{fontspec}
\usepackage[math-style=ISO]{unicode-math}

\setmathfont{Latin Modern Math}
\setmainfont{Latin Modern Roman}

\begin{document}

$$\mu + \symrm{\mu} - γ + \symrm{γ} + \Pmuon$$

• For completeness, \symup works too. – Davislor Jun 5 at 1:01