Why does make4ht mathjax convert AMS gather environment to html code?

Question

With the mathjax option, make4ht fails to render the following:

\documentclass{article}

\usepackage{amsmath}

\begin{document}
\begin{gather}
    E=mc^2\\
    e^{i\pi}+1=0
\end{gather}
These equations are amazing.
\end{document}

I believe MathJax can handle the gather environment verbatim, but the mathjax option seems to try and fail to convert the equations into images.

Am I missing something obvious?

Answer 1

The default TeX4ht configurations turn gather environment into pictures. This configuration file should fix that:

\Preamble{xhtml}
\ConfigureEnv{gather}{}{}{}{}
\begin{document}
\EndPreamble

Result:

I've fixed this issue in TeX4ht sources, so this configuration should be unnecessary soon, if you use TL 2021.