Very unexpected overleaf bibliography behavior, citation not rendering

Question

I am having a very strange problem with my .bib file in overleaf.

Some of my citations don't show up in the Works Cited in my rendered paper, even though they are in the .bib file, and are cited in text both with \cite{} and \nocite{}, exactly the same as several other citations which do render correctly.

As I was trying to solve this I noticed that if I change one letter in the first author's name, a particular citation suddenly does render!

The correct citation is :

@article{xia_2017,
    author = {Xide, Xia and Brian, Kulis},
    year = {2017},
    title = {W-Net: A Deep Model for Fully Unsupervised Image Segmentation},
    eprint={1711.08506},
    archivePrefix={arXiv},
    primaryClass={cs.CV}
}

This is cited in text as \nocite{xia_2017}, but does not show up in the Works Cited and I get a warning saying "Package natbib Warning: Citation `xia_2017' undefined on input line 150"

However, if I change only one letter in the author's name, it works! For instance,

@article{xia_2017,
    author = {Mide, Xia and Brian, Kulis},
    year = {2017},
    title = {W-Net: A Deep Model for Fully Unsupervised Image Segmentation},
    eprint={1711.08506},
    archivePrefix={arXiv},
    primaryClass={cs.CV}
}

Renders correctly with the same call in the body of the text.

What is going on here?

Edit: As an update, this is NOT just this citation. Adding the letter 'M' before the first author's first name causes the citation to render correctly (though misspelled, obviously) for ALL of the citations that are otherwise not rendering.

Edit 2: Below is the text for the minimum .main and .bib files that reproduce this issue.

main.tex:

\documentclass{article}
\usepackage{natbib}
\bibliographystyle{abbrvnat}

\title{Example document}

\begin{document}

\maketitle

\nocite{Muller_1986}
\nocite{Rieutord_2007}
\nocite{ronneberger_2015_works}
\nocite{ronneberger_2015_fails}
\nocite{Strous_1995}

\bibliography{works_cited}{}

\end{document}

works_cited.bib:

@INPROCEEDINGS{Strous_1995,
       author = {{Strous}, L.~H.},
        title = "{Feature Tracking: Deriving Horizontal Motion and More}",
    booktitle = {Helioseismology},
         year = 1995,
       editor = {{Hoeksema}, J.~T. and {Domingo}, V. and {Fleck}, B. and {Battrick}, Bruce},
       series = {ESA Special Publication},
       volume = {376},
        month = jun,
        pages = {213},
       adsurl = {https://ui.adsabs.harvard.edu/abs/1995ESASP.376b.213S},
      adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}

@article{Bovelet_2001,
    author = {Bovelet, B. and Wiehr, E.},
    year = {2001},
    month = {06},
    pages = {13-26},
    title = {A New Algorithm for Pattern Recognition and its Application to Granulation and Limb Faculae},
    volume = {201},
    journal = {Solar Physics},
    doi = {10.1023/A:1010344827952}
}

@article{Muller_1986,
author = {Muller, Richard and Thierry, Roudier},
year = {1986},
month = {09},
pages = {11-26},
title = {Structure of the solar granulation},
volume = {107},
journal = {Solar Physics}
}

@article{ronneberger_2015_works,
      title={U-Net: Convolutional Networks for Biomedical Image Segmentation}, 
      author={MRonneberger, Olaf and Fischer, Philipp and Brox, Thomas},
      year={2015},
      eprint={1505.04597},
      archivePrefix={arXiv},
      primaryClass={cs.CV},
      journal = {arXiv}
}

@article{ronneberger_2015_fails,
      title={U-Net: Convolutional Networks for Biomedical Image Segmentation}, 
      author={Ronneberger, Olaf and Fischer, Philipp and Brox, Thomas},
      year={2015},
      eprint={1505.04597},
      archivePrefix={arXiv},
      primaryClass={cs.CV},
      journal = {arXiv}
}

@article{Rieutord_2007,
    doi = {10.1051/0004-6361:20066491},
    url = {https://doi.org/10.1051%2F0004-6361%3A20066491},
    year = 2007,
    month = {may},
    publisher = {{EDP} Sciences},
    volume = {471},
    number = {2},
    pages = {687--694},
    author = {M. Rieutord and T. Roudier and S. Roques and C. Ducottet},
    title = {Tracking granules on the Sun{\textquotesingle}s surface  and reconstructing
         velocity fields},
    journal = {Astronomy {\&}amp$\mathsemicolon$ Astrophysics}
}

Answer 1

I get a warning from bibtex: Warning--I didn't find a database entry for "xia_2017" then an error from tex ! Undefined control sequence. <recently read> \mathsemicolon

Also an error from url, so fixing the unrelated errors produces an example:

\documentclass{article}
\usepackage{natbib}
\bibliographystyle{abbrvnat}
\newcommand\mathsemicolon{;}
\usepackage{url}
\title{Example document}

\begin{document}

\maketitle

\nocite{Muller_1986}
\nocite{Rieutord_2007}
\nocite{ronneberger_2015_works}
\nocite{ronneberger_2015_fails}
\nocite{Strous_1995}
\nocite{xia_2017}

\bibliography{works_cited}{}

\end{document}

running pdflatex, bibtex, pdflatex, pdflatex

produces a warning about the undefinined 2017 citation, but both the 2015 citations work as expected: