I have had good experience with tex4ht (htlatex), but in a new article I am compiling, there are random cases where inline and display mode matrices are in italics when using $\mathbf{L}$ for inline and e.g.
\begin{equation}
\hat{\mathbf{E}}
\end{equation}
for display mode. Is this likely due to not using $$ or \[ ... \] for html projects?
tex4htconfiguration compiles your example to picture which keeps the used style. other solutions that should work is to use "mathjax" or "mathml,mathjax"tex4htoptions on the command line or in the configuration file – michal.h21 Jun 28 '19 at 06:57