How to use \MakeUppercase in combination with the bm package in LaTeX 2022-11-01

I am trying to submit LaTeX sources to arXiv and I ran into some issues.My project lives in overleaf where I am using TeX Live 2021 and everything compiles without any errors or warnings (except from overfull or underfull boxes).However, when I tried to process the source files on arXiv, the \MakeUppercase leads to a compilation error.

I was able to replicate the error locally using the following snippet, suggesting that the combination of the bm package and the \MakeUppercase is the problem:

\documentclass{standalone}\usepackage{amsmath}\usepackage{bm}\begin{document}Test plain: $\bm{x}$.%replacing \bm by \boldsymbol resolves the issueTest upper: $\bm{\MakeUppercase{x}}$.\end{document}

However, I was unable to replicate this issue inside overleaf (trying both TeX Live 2022 and 2023).After some more digging, I figured out that my TeX Live (2023) distribution uses LaTeX2e 2022-11-01, whereas overleaf uses 2022-06-01.Also, arXiv seems to be using 2022-11-01.

While looking around, I noticed there have been some changes to \MakeUppercase that caused issues with the microtype package.Furthermore, I found this Github issue on issues with the Greek alphabet.I am not sure if these issues are related, but they definitely seem relevant.

This comment in the Github issue seems to suggest that it is better/easier to fix the code than to create a workaround.However, (to the best of my knowledge) I cannot change the LaTeX version on the arXiv servers.Therefore, it seems like I will need some sort of workaround after all.

One solution I could think of would be to replace \usepackage{bm} by something like \let\bm\boldsymbol, but I'm unsure whether this would have any undesired effects to the typesetting.Is this a reasonable solution, or are there other options I should consider to upload my project to arXiv?

More generally, I would also be interested to understand why \MakeUppercase causes this many issues recently.E.g. Is there a list of packages that are known to have issues with \MakeUppercase and is there a more general solution?

update: On version 2022-11-01 patch level 1, \MakeUppercase also fails with \boldsymbol with the following error(s):

/home/hoedt/Downloads/tmp/test.tex:10: Undefined control sequence.\MakeUppercase    [#1]#2->\let \kernel@saved@oe                                                 \oe \let \oe \OE \@@text@cas...l.10 Test upper: $\boldsymbol{\MakeUppercase{x}}                                                $./home/hoedt/Downloads/tmp/test.tex:10: Undefined control sequence.\MakeUppercase    ...#2}\let \oe \kernel@saved@oe l.10 Test upper: $\boldsymbol{\MakeUppercase{x}}                                                $./home/hoedt/Downloads/tmp/test.tex:10: Extra }, or forgotten $.\bm@command ...\space \@spaces \@spaces \@spaces }                                                  {LaTeX Warning: Command \p...l.10 Test upper: $\boldsymbol{\MakeUppercase{x}}                                                $.