Nextjs middleware matcher

So I have a lot of internal i18n URLs and I created a function for generating those URLs.. and then used it in middleware mathcer like this:

export const config = {
    matcher: [
        '/((?!_next|api|favicon.ico|assets|sw.js|site.webmanifest).*)',
        ...generateMatchers(),
    ],
};

And it did not work.

I reduced generateMatchers to this:

const generateMatchers = () => {
    return ['/((?!_next|api|favicon.ico|assets|sw.js|site.webmanifest).*)',];
};

And matcher to this:

export const config = {
    matcher: [
        ...generateMatchers(),
    ],
};

And found out that THAT did not work. Yet it worked just fine when I did this:

export const config = {
    matcher: [
        '/((?!_next|api|favicon.ico|assets|sw.js|site.webmanifest).*)',
    ],
};

Why would that be? Is this a bug I should report ( NextJS 14.2 versions )