Hi @dimalifragis,
Thanks for your reports. First, I can assure you that PHP 8, WordPress 6.1, and FastCGI shouldn’t be a problem here; I have tested with all of these environments.
I also tried disabling garbage collection (setting Cache Timeout to 0), even though my understanding is that in preload mode this setting should be irrelevant. This seems to have no effect.
I agree that Garbage Collection shouldn’t have an effect on this, however @bruceallen suggested it as we recently had another forum user report that having GC set to anything other than 0 was deleting their Super Cache files for reasons we haven’t yet tracked down.
Thank you both for checking and reporting on this setting, we can rule this out as a factor in your cases.
In order to track down what is happening, would you mind trying out DEBUG mode and triggering a Preload?
We have instructions for enabling DEBUG mode here: https://github.com/Automattic/wp-super-cache/wiki/How-to-enable-debug-mode
Set your preload time to 0 to turn off automatic refreshing, and then click the “Preload Now” button. Give it a few minutes, then check out the DEBUG log for information.
It should look something like this:
wp_cron_preload_cache: got 100 posts from position 0.
supercache dir: /home/test-user/example.com/subdir/wp-content/cache/supercache/example.com/subdir/sample-page/
wp_cron_preload_cache: fetched https://example.com/subdir/sample-page/
supercache dir: /home/test-user/example.com/subdir/wp-content/cache/supercache/example.com/subdir/2023/03/06/hello-world/
wp_cron_preload_cache: fetched https://example.com/subdir/2023/03/06/hello-world/
wpsc_delete_files: deleting /home/test-user/example.com/subdir/wp-content/cache/supercache/example.com/subdir/
wpsc_get_realpath: directory does not exist - /home/test-user/example.com/subdir/wp-content/cache/blogs/
wpsc_delete_files: reading files: ..
wpsc_delete_files: reading files: sample-page
wpsc_delete_files: reading files: 2023
wpsc_delete_files: reading files: .
wpsc_delete_files: remove directory /home/test-user/example.com/subdir/wp-content/cache/supercache/example.com/subdir/
Take a look at the pages it’s fetching – make sure it appears to be fetching all of the posts you expect to be preloaded, and check that there are no lines indicating files are being deleted (note: “remove directory” just indicates it will be removed _if empty_ and is not something to be worried about).
If you’d like help interpreting your debug mode output, please feel free to send it to me – but please be sure to edit out any private information you do not want to post on this forum (e.g.: URLs, private directory names, etc).
