APCU Elementor

Hello @narolles !

To be honest, this is the first time we’ve had this feedback. And it would be the first time this plugin has shown incompatibility with a page builder…

Could you explain in detail how this manifests itself? With which Elementor options? What are the symptoms?

Many thanks in advance.

The symptoms you describe do not appear to be caused by LS Cache, Elementor, or APCu Manager.

It may be due (at 90% chance) to a problem with APCu or the server itself. And it’s revealed when you use APCu…

Can you tell me or describe where this site is hosted, with what web server, on what architecture type (physical, vps, instance, docker, kube, etc.), with or without load-balancing, etc. ?

Thanks

Hi @narolles,

Thank you for the detailed information — it’s very helpful to understand the context of the issue.

✅ Summary of the reported issue:
When you enable a persistent object cache via APCu (using my APCu Manager plugin), you notice intermittent CSS inconsistencies on Elementor pages (hosted on LiteSpeed), even though the generated CSS files do exist on the server. The issue disappears when APCu is disabled.🔎 What we know so far

1. There is no fatal error, only styles that are not applied correctly.
2. The issue only occurs when APCu is enabled, not when using just OPcache + LiteSpeed page cache.
3. The CSS files are physically present, but in some cases they are not interpreted/applied as expected by the browser.

📌 Likely explanation

This behavior looks like a persistent object cache returning stale data (possibly Elementor transients or style-related data stored in APCu), which may lead to incorrect or partial CSS application. Elementor’s external CSS generation relies on several internal steps and transients. If outdated data remains in APCu, it could interfere with how these CSS files are generated or referenced without breaking the page entirely.

👉 This does not necessarily indicate a “direct” incompatibility between APCu and Elementor, but rather an interaction issue related to object cache behavior and cache invalidation timing.💡 Things you can test to help diagnose

To better isolate the issue, could you please let us know:

1. Whether you are using specific Elementor options related to CSS/JS handling (e.g. external CSS vs inline CSS)?
2. Whether you have disabled Elementor’s internal cache in the performance settings?
3. Whether adding a unique WP_CACHE_KEY_SALT in wp-config.php changes anything (this is important when multiple persistent caches or multiple sites share the same APCu space).
   Example:define( 'WP_CACHE_KEY_SALT', 'unique-string-for-this-site' );

📍 Conclusion 1

At this stage, this does not appear to be a fundamental incompatibility between APCu Manager and Elementor, but rather a specific interaction between persistent object caching and Elementor’s dynamic CSS management, especially on certain environments (notably LiteSpeed).

📍 Conclusion 2

Yes, that AI-generated answer makes no sense. Just like the answers to the questions I asked you.
From now on, I will no longer respond to tickets generated by AI. It’s too much of a waste of time (Brandolini warned us).
And if you think my point of view is stupid, just ask your AI to find the answer.