Screen shots at

https://tex.stackexchange.com/questions/730525/adding-usepackagesubcaption-makes-tex4ht-not-correctly-align-caption-below-im

This MWE

----------------------------
\documentclass[12pt]{book}
\usepackage{graphicx}
\usepackage{framed}
\newcommand{\addImage}[4]
{
\begin{figure}
\centering
\begin{framed}
\includegraphics[width=#2\textwidth]{#3}\caption{#4}
\end{framed}
\end{figure}
}%
\usepackage{subcaption}
\begin{document}
\addImage{1}{0.3}{example-image-a}{Phase line diagram}
\end{document}
-------------------

Compiled with lualatex, gives correct output, with caption below the image

enter image description here

But compiled with tex4ht using the command

make4ht -ulm default -a debug A.tex 'mathjax,htm'

gives this

enter image description here

Removing \usepackage{subcaption} from the code, now tex4ht gives correct output

enter image description here

Is there a workaround for tex4ht?

TL 2024, updated 3 days ago.