PKGBUILD highlighting messed up by ) in strings

A ) in strings, specially common in optdepends, completely messes up the syntax highlighting following that line. And, actually, strings in general are not highlighted correctly.

In a new VM, I did the following: (To make absolutely certain no custom config is interfering)

pacman -Sy
pacman -S pacman-contrib asp
asp checkout neovim
vim neovim/repos/trung/community-x86_64/PKGBUILD
:set ft=PKGBUILD

And the result is... this:

As you can see, most of the strings are not highlighted as strings and after the optdepends, everything is completely messed up.

I have played around with it a bit and simply pasting the shSingleQuote definition (found in /usr/share/vim/vim82/syntax/sh.vim) at the end of /usr/share/vim/vimfiles/syntax/PKGBUILD.vim, fixes it for the most part:

Now, I have not the slightest idea why re-stating an already existing definition helps, or why it has to be after the optdepends definition and does nothing if placed before, but those are my findings. I originally intended on submitting a merge request with a fix, but I don't understand this behaviour and am out of my depth here. Sure, pasting the definition again at the end does work, but this doesn't strike me as a good solution.