I think this has to do with how you export CoolBtn from home.jsx, particularly in that you’re not exporting it.
maybe this page can help
it says:
the default export can be imported with any name. For example:
// file test.js
const k = 12;
export default k;
// some other file
import m from "./test"; // note that we have the freedom to use import m instead of import k, because k was default export
console.log(m); // 12
which looks like what’s happening here. you have an export default for the “entire menu page,” and you import it under a different name CoolBtn