Thank you for you attention.
Actually, it works correctly if I use the default setting (Cached pages will be valid for = “0”). But if I put other value (for example 720), my website will be very slow as there is not using any cache plugin, and there will show nothing on the “Compute the cache size”.
If you interested, here is my blog:
https://graphicslearning.com
And these are the plugins it using:
– All In One WP Security
– BackUpWordPress Backup Plugin
– Bad Behavior
– BJ Lazy Load
– Contextual Related Posts
– Delightful Downloads
– Easy Digital Downloads
– Fast Secure Contact Form
– Force Regenerate Thumbnails
– Hyper Cache
– Lightbox Plus Colorbox
– Nano Plugin Manager
– NoSpamNX
– SEO Ultimate
– ShortCodes UI
– Widgets in Columns
– Wordfence Security
– Wp-Insert
– WP Slimstat
– XML Sitemap & Google News feeds
Let me know if you want to test the bug, because it will need to put some value on the “Cached pages will be valid for” to show the bug.