Wordpress homepage returning error 404 code but the page is fine

My WordPress website's homepage, https://fandangoph.xyz is returning error 404 even the page is working. Other pages beside from homepage is working well and returning code 200.

I tried all troubleshooting methods I saw in the internet like clearing cache in cloudflare and from my server.

The last thing I did is by putting this code in my WordPress website but the issue still persists:

<?php

include('blog/wp-blog-header.php');

?>
Is there any way to fix this? I spend a whole day figuring it out but no luck.

Server: Linode (Ubuntu) Webserver: Openlitespeed CDN: Cloudflare