Namecheap, Vercel, and Next.js CORS error on custom domain

Question

I have my api opended up to the public for an api. I have a .vercel.app that works fine with no CORS errors. However, with my custom .com domain I am getting CORS errors. The two errors are:

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at commercesite.net/api/keys. (Reason: CORS header ‘Access-Control-Allow-Origin’ missing). Status code: 308.

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at commercesite.net/api/keys. (Reason: CORS request did not succeed). Status code: (null).

Here is my next.config.js file:

/* eslint-disable */

/** @type {import('next').NextConfig} */
const nextConfig = {
    async headers() {
        return [
            {
                source: "/api/:path*",
                headers: [
                    { key: "Access-Control-Allow-Credentials", value: "true" },
                    { key: "Access-Control-Allow-Origin", value: "*" },
                    {
                        key: "Access-Control-Allow-Methods",
                        value: "GET,DELETE,PATCH,POST,PUT,OPTIONS",
                    },
                    {
                        key: "Access-Control-Allow-Headers",
                        value:
                            "X-CSRF-Token, X-Requested-With, Accept, Accept-Version, Content-Length, Content-MD5, Content-Type, Date, X-Api-Version, Authorization, id, filters, Api-Key",
                    },
                ],
            },
        ];
    },
    webpack: (
        config,
        { buildId, dev, isServer, defaultLoaders, nextRuntime, webpack }
    ) => {
        nextRuntime = "nodejs";
        return config;
    },
    eslint: {
        ignoreDuringBuilds: true,
    },
    typescript: {
        ignoreBuildErrors: true,
    },
};
module.exports = nextConfig;

Everything works fine on the Vercel domain but not the custom Namecheap one.

The custom domain is accesible just not through a third party site.

Note: The url actually ends in .com SO is just requiring a .net domain.