Apache ignores all connections on port 80. Returns strange error JSON instead

I am currently trying to migrate to a new server, and found that the old server has started to ignore any of my config relating to port 80, and instead chooses to return the following no matter what:

HTTP/1.1 404 Not Found
Date: Thu, 22 Jan 2026 15:20:24 GMT
Server: Apache/2.4.66 (Unix) OpenSSL/3.6.0 mod_wsgi/5.0.2 Python/3.14 PHP/8.5.2
Access-Control-Allow-Origin: *
Content-Type: application/json
Content-Length: 51
Connection: close

{"code":40401,"http":404,"error":"page not found"}

The new server (using an identical rewrite, listed below) works perfectly fine, and using a different port on the old also works.

<VirtualHost *:80>
    #        ^ Old server also has *:8448 here for testing
    ServerName default
    ServerAlias *

    RewriteEngine On
    RewriteCond %{HTTPS} !=on
    RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
</VirtualHost>

I can attach additional files/context on request.