[Plugin: WP Super Cache] Caching not working

I’m using php to cache files as i’m using category/postname permalinks

Test your cached website by clicking the test button below.

Fetching https://wordpresssites.net/ to prime cache: OK

Fetching first copy of https://wordpresssites.net/: OK (1.html)

Fetching second copy of https://wordpresssites.net/: OK (2.html)

The pages do not match! Timestamps differ or were not found!

Caching doesn’t seem to be working

Directly Cached Files

I also get this message. how do i fix this?

Warning! /home2/wordpri4/public_html/ is writable. Please make it readonly after your page is generated as this is a security risk.

I also ran a yslow speed check which is the same score before activating the plugin

https://www.ads-software.com/extend/plugins/wp-super-cache/