"demohigh" environment can not contain the character "@"

[Meiting Wang]

Hello Mr. Lu. I find that "demohigh" environment can not contain the character @, but "codehigh" environment can.

Could this be a bug?

Thanks in advance

PS.
my system: win10
Tex Live version: TeX 3.141592653 (TeX Live 2022)
tlmgr update time: August 6, 2022
My MWE:

\documentclass{article}
\usepackage{codehigh}
\CodeHigh{style/main=azure9,style/code=azure9}


\begin{document}

\makeatletter
\@for\sun:={rising,setting}\do{The sun is \sun. }
\makeatother

\begin{codehigh}
\makeatletter
\@for\sun:={rising,setting}\do{The sun is \sun. }
\makeatother
\end{codehigh}

\begin{demohigh}
\makeatletter
\@for\sun:={rising,setting}\do{The sun is \sun. }
\makeatother
\end{demohigh}

\end{document}

[lvjr]

Thanks for your report (again). I will look into it later.