I have the following 'MWE.tex' file where I defined underscore with \catcode'_=12:
\documentclass{article}
\catcode`_=12
\begin{document}
Text containing underscore between parenthesis (_)
\end{document}
When I tried to convert this 'MWE.tex' file into html using Make4ht with the following command:
make4ht MWE.tex
I obtain this results in HTML (the underscore is not well converted):
Text containing underscore between parenthesis (˙)
My web navigator displays this:

I there a way to obtain a good conversion of the underscore in this case?

-l... My setup could be wrong. I have the v0.3d version of make4ht and working on Linux Unbuntu 20.04 LTS (stricly speacking on a Windows Subsystem Linux). – zetyty Feb 18 '22 at 12:20apt install texlive-fullandapt updatebefore. When I dotex --versionI getTeX 3.14159265 (TeX Live 2019/Debian) kpathsea version 6.3.1I will try to upgrade something anyway. – zetyty Feb 18 '22 at 13:16config.cfgfile? Especially why\catcodeˋ_=13and not=12? – zetyty Feb 18 '22 at 18:21