I have 2 json files, /data/contentDownloads.json and /data/links.json

This is my helper to get the json files

import { unstable_cache } from "next/cache";
export async function getJson(
  fileName: string,
  tag?: string,
  revalidate?: number
) {
  const content = unstable_cache(
    async () => {
      const file = await fs.readFile(
        process.cwd() + `/data${fileName}.json`,
        "utf8"
      );
      const locContent = JSON.parse(file);
      return locContent;
    },
    ["json"],
    {
      tags: tag ? [tag] : ["data"],
      revalidate: revalidate ? revalidate : false,
    }
  )();
  return content;
}

I need the tags so I can revalidate them. Now if I call the function with /contentDownloads, "content" I get the correct data and can also revalidate correctly, but doing "links", "link" provides the same data as the content one, any idea why this seems to be happening?