wowlayers

@dilirity thanks for taking the time to write.

In the end it seems WP Super Cache, creates separate folders for each domain, so my issue is resolved ??

I tried this filter, I am almost sure this is the one, but it doesn’t log anything.

add_filter('wp_cache_served_cache_file', 'modify_served_cache_file', 10, 1);

function modify_served_cache_file($cache_file) {
    // Inspect the cache file being served
    error_log("Serving cache file: " . $cache_file);

    // Modify the cache file path or manipulate its content if needed
    // Example: Read and replace content dynamically
    if (file_exists($cache_file)) {
        $cache_data = file_get_contents($cache_file);

        // Example: Replace the domain dynamically based on the request
        $current_domain = $_SERVER['HTTP_HOST'];
        $cached_domain = 'primary-domain.com'; // Replace with your cache domain

        // Replace domain in cached data
        $cache_data = str_replace($cached_domain, $current_domain, $cache_data);

        // Save the modified content back to the file (optional)
        file_put_contents($cache_file, $cache_data);
    }

    // Return the modified or original cache file path
    return $cache_file;
}

This is my WP_DEBUG Setup

define( 'WP_DEBUG', true );
define( 'WP_DEBUG_LOG', true );
define( 'WP_DEBUG_DISPLAY', false ); // Prevents errors from displaying on the frontend
@ini_set( 'log_errors', 1 );
@ini_set( 'display_errors', 0 ); // Prevents errors from displaying on the frontend

WP Super Cache is set to operate in Simple Mode.

Any ideas would help ??