Custom Errors not loading CyberPanel + Cmsms


I have set up my VPS with CyberPanel, and it uses OpenLiteSpeed.
I have then installed Cmsms to be my "cms" solution, just like WordPress.
But I'm facing an issue where pages that do not exist, show a blank page with the code 200.
Saying that the page works fine.
But in reality, it would have shown 404.

I have the 403 workings fine on the cms, but

By editing the ID from 212 to 112 it should have shown 404, but it shows a blank page instead.
The cmsms team has said that it should work.

I have run my site on Litespeed before, and it was working there. (I have re-written the htaccess after the change)
I have included the htaccess as a file also.



Below are my custom error pages.
The two first are from the cms.
The last one is a standalone file.

404 Not Found
403 Forbidden
500 Internal Server Error





My guess for 403 works is because it won't hit the following rules. Whereas, ID 112 hit this.
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteRule ^(.+)$ index.php?page=$1 [QSA]
Maybe this cms has a build-in 404 page somewhere, so it redirected to the build-in 404 page with a 200 status code.