reference and images

https://tex.stackexchange.com/questions/601030/tex4ht-in-tl-2021-gives-error-on-code-that-compiles-ok-with-lualatex

Here is a MWE to reproduce it

============================
\documentclass[12pt]{article}
\usepackage{graphicx}
\begin{document}
The following is plot of solution

\begin{figure}[h]
\centering
\includegraphics[scale=0.45]{example-image}
\caption{$\displaystyle {y \left(x \right) = -\frac{\left(\left(\left\{\begin{array}{cc}
{\mathrm e}^{-2 x} & x \le 1
\\
{\mathrm e}^{-2} & 1<x
\end{array}\right.\right)-7\right) {\mathrm e}^{2 x}}{2}}$
}
\end{figure}
\end{document}
=================

The above compiles OK with lualatex

The same file in tex4ht gives this error in TL 2021

(/usr/local/texlive/2021/texmf-dist/tex/generic/tex4ht/html4-math.4ht)
(/usr/local/texlive/2021/texmf-dist/tex/generic/tex4ht/html5.4ht)) (./foo3.aux)
[1] [2]
l.16 --- TeX4ht warning --- File `"example-image.xbb"' not found ---
l.16 --- TeX4ht warning --- Cannot determine size of graphic in "example-image.
xbb" (no BoundingBox) ---
! Argument of \im:g has an extra }.
<inserted text>
\par
l.22 }

?

This is on Linux.