Incorrect spacing after "et al." in parenthetical citations

[capnrefsmmat]

Explain the problem.

Consider the following test file:

---
title: Test
bibliography: test.bib
---

This fact is well-known [@smith].

and the following test bibliography:

@article{smith,
author = {Smith, John and Doe, Jane and Doe, John and Humperdinck, Englebert},
title = {Title},
year = {2025},
journal = {Journal of Irreproducible Results},
volume = {7},
number = {4}
}

I then run pandoc --citeproc -o test.tex test.md to generate the LaTeX output from this, and get the following:

This fact is well-known (Smith et al. 2025).

\protect\phantomsection\label{refs}
\begin{CSLReferences}{1}{1}
\bibitem[\citeproctext]{ref-smith}
Smith, John, Jane Doe, John Doe, and Englebert Humperdinck. 2025.
{``Title.''} \emph{Journal of Irreproducible Results} 7 (4).

\end{CSLReferences}

By default, TeX places extra space after periods, assuming they are sentence breaks. Consequently, "Smith et al. 2025" has a funny extra-wide space in between "al." and "2025":

On the other hand, if I write an equivalent LaTeX document using BibLaTeX with \parencite{} and the authoryear style, it suppresses the extra space:

I believe this is the correct behavior: "et al." is not ending a sentence, so there should not be a sentence space after it, only a normal one. Perhaps Pandoc should emit "Smith et al.\ 2025", which makes TeX treat it as a normal space, not a sentence space.

Pandoc version?
pandoc 3.8.2.1 on MacOS.

[AlbertLei]

u can use the --natbib or --biblatex flag (instead of --citeproc), for better latex bibliography formatting.
Docs here

i use --natbib when output latex.
two caveats about --natbib:

• you may need to use latexmk --pdf-engine latexmk or other latex build process u are familiar with
• i remember that the natbib is more picky than citeproc about the bib directory format. Eg, -M 'bibliograph y:./config/references.bib' may not work for --natbib, but -M 'bibliography:config/references.bib' is ok.