The updated Make4ht with support for problematic fonts is not in TeX Live.

Using the following source, \textit and \it are
treated differently in the .odt result.
After conversion of the .odt file to .docx, all italics
in the reference section are converted to roman
(but not in the main text).
This apparently does not happen without
\renewcommand{\rmdefault}{ptm}

(But my full article source cannot be compiled by
make4ht if I comment out this line. No problem with
ordinary platex. I will post this issue separately
if I can find a minimum set.)

What is wrong?

\documentclass[12pt,a4paper]{article}

\usepackage[comma,colon]{natbib}

\renewcommand{\rmdefault}{ptm}

\begin{document}

\textit{test italic} \& {\it test italic}

\begin{thebibliography}{}

\bibitem[{Alekseenko}(2016)]{ale16baikalraptorphd}
{Alekseenko}, M.~N. (2016) \textit{Ecological aspects of fall migration of
raptors in south Baikal migration corridor.} PhD Thesis, Bratsk State Univ.,
Bratsk (in Russian.)

\bibitem[{Antonov}(2020)]{ant20middleamur}
{Antonov}, A.~I. (2020) Expansion of new bird species in the {Middle Amur}
region at the end of the 20th century: the role of climatic changes. {\it
Rus. J. Ornithol.} 29: 4819-4827 (in Russian.)

\end{thebibliography}

\end{document}