Locale slug is added to api and other routes outside of app dir

[J4v4Scr1pt]

What version of this package are you using?
2.6.0

What operating system, Node.js, and npm version?
pnpm: 8.8.0
node: 20.7.0
Windows 10

What happened?
I have built my application not to utilize the Internationalization (i18n) Routing rather using the queryParam from next-translate.
Everything works as expected, but I get this error and similar on the Node-server. I don't want or need the api to be prefixed with locale. Or any page for that matter.

Failed to write image to cache /en-US/api/health [Error: ENOENT: no such file or directory, mkdir '/app/.next/server/app/en-US'] {errno: -2,code: 'ENOENT',syscall: 'mkdir',path: '/app/.next/server/app/en-US'}

What did you expect to happen?
That it should not add the prefix to the URL.
To have a setting or way to opt-out of automatic adding the locale to the URL.

Are you willing to submit a pull request to fix this bug?
I would but, my knowlage on this very limited

Folder structure

Code
middleware:

export default async function middleware(request: NextRequest) {
	const locale = request.nextUrl.locale || i18n.defaultLocale;
	request.nextUrl.searchParams.set('lang', locale);
	request.nextUrl.href = request.nextUrl.href.replace(`/${locale}`, '');
	return NextResponse.rewrite(request.nextUrl);
}

export const config = {
	matcher: ['/((?!Login/|api|_next/static|_next/image|favicon.ico).*)', '/'],
};

i18n:

module.exports = {
	locales: ['en-US', 'da-DK', 'fi-FI', 'sv-SE', 'nb-NO', 'de-DE'],
	defaultLocale: 'en-US',
	pages: {
		'*': ['common'],
		'/(main-app)': ['home'],
		'/(main-app)/Overview': ['overview'],
	},
	logBuild: false,
	loadLocaleFrom: (lang, ns) =>
		// You can use a dynamic import, fetch, whatever. You should
		// return a Promise with the JSON file.
		// Needed because standard notation for culture is e.g. en instead of en-US
		import(`./locales/${lang}/${ns}.json`).then((m) => m.default),
};

next.config:

/** @type {import('next').NextConfig} */

const nextTranslate = require('next-translate-plugin');

const nextConfig = {
	basePath: '/next',
	output: 'standalone',
};

module.exports = nextTranslate(nextConfig);