This isn't a new issue; not even to me!
https://news.ycombinator.com/item?id=38946967
> chandlerswift on Jan 11, 2024 | on: Conditional Git Configuration
>
> I'd attempted to configure this some time back, but never gotten it
> working, and this was the kick in the pants I needed to finally get
> it working!
>
> In case anyone is stuck in the same way that I was, the trailing
> slash at the end (which I had previously omitted, not realizing) is
> necessary for this to work. The docs[0] mention this, but I'd managed
> to repeatedly miss it:
>
> > If the pattern ends with /, * will be automatically added. For
> > example, the pattern foo/ becomes foo/*. In other words, it matches
> > "foo" and everything inside, recursively.
>
> [0]: https://git-scm.com/docs/git-config#Documentation/git-config...
:doh:
