WP Homepage Downloading a File

OK, this is weird. I have been having issues with redis cache forwarding one site to another. I think I have that sorted, but now my homepage just downloads a file, this file:

<?php
/**
 * Front to the WordPress application. This file doesn't do anything, but loads
 * wp-blog-header.php which does and tells WordPress to load the theme.
 *
 * @package WordPress
 */

/**
 * Tells WordPress to load the WordPress theme and output it.
 *
 * @var bool
 */
define('WP_USE_THEMES', true);

/** Loads the WordPress Environment and Template */
require( dirname( __FILE__ ) . '/wp-blog-header.php' );

All of the subpages work, it is only the homepage that does this.

Here are the URL’s:

Homepage:
https://1123interactive.com/

Subpages:
https://1123interactive.com/about/
https://1123interactive.com/contact/

I have flushed all cache (caches?) and I have deleted all cache files. It still does this. Doesn’t appear to be a site-wide PHP issue, since the sub-pages load.

I am pulling my hair out, as such any help would be most appreciated. Thank you!