Routing problem, got 404 while the route is present on the directory.

[Auvberon]

Summary

I’ve recently taken over the development of a project started by someone else, and I’ve encountered this weird issue regarding the app routing that I need some help with.

When testing the project with postman, and hit the '/api/file/upload' it returns 404 error. But when I hit the API with '/file/upload/' it returns 200.

I've read the similar issue with this #74213. Any help for this issue?

Thank you.

Additional information

Tree of the project : 
/src
└── /app
    └── /api
        └── /file
            └── /upload
                └── route.ts

----------------------------------------------------------------
The Middleware

export async function middleware(request: NextRequest) {
    if (request.nextUrl.pathname.includes("/api") || request.nextUrl.pathname.includes("/app")) {
        if (request.cookies.get("appSession")) {
            return NextResponse.next()
        } else {
            return NextResponse.error()
        }
    }

    if (request.cookies.get("appSession")) {
        return verifyJwt(request.cookies.get("appSession")!.value)
    }
    if (!request.cookies.get("appSession")) {
        return login()
    }
    const requestheader = new Headers(request.headers)
    requestheader.set("X-Pathname", request.nextUrl.pathname)

    return NextResponse.next({
        request: {
            headers: requestheader
        }
    })
}

----------------------------------------------------------------
The next.config.mjs

const rulesToProcess = [/\.m?ts/, /\.(ts|cts|mts)$/].map(String);
const dirToIgnore = /src\/lib\/ui-temp/;

/** @type {import('next').NextConfig} */
const nextConfig = {
    pageExtensions: ["ts", "tsx"],
    reactStrictMode: false,
    experimental: {
        instrumentationHook: true,
    },
    webpack: (config) => {
        config.module.rules = config.module.rules.map((rule) => {
            if (rule !== "..." && rulesToProcess.indexOf(String(rule.test)) > -1) {
            rule.exclude = [dirToIgnore];
        }
            return rule;
        });
        return config;
    }
};

export default nextConfig;

Example

No response

[icyJoseph]

What's the Next.js version? weird that the middleware checks for /app...