title: Wordpress File permission issue all of a sudden
body: <p>My website had been working well. But recently I started to see some abnormalities.</p>
  <p>When I upload a media file, it says the file can't be moved to upload/2022/08; When I create a new post, the featured image choice section on the backend are gone; On frontend, plugin WP-SCSS is reporting file permission issue on the cache folder;</p>
  <p>I had to manually change the related folder from 0755 to 0777 to solve these issues. But why all of a sudden it requires 0777 while it never had? The only change I made recently to the server is doing some package upgrade for my linux server. It was a one-click-go and I didn't take a closer look to what had been upgraded but I do remember seeing most items are related to PHP8.0 or PHP8.1. Could this be the reason the file permission issue is acting up?</p>