WP_CACHE is not set? It is!

Hi guys, after installing/uninstalling Jetpack in my site (Jetpack made it slower), my loading times went from below 1 second to almost 3 seconds ??
On settings I see the message (‘WP_CACHE’, true); is not set in wp-config.php, even with that line set manually on the mentioned file.

What could I do to solve this? Another of my sites, on the same server, is having no problems with Cache Enabler, so it’s not server related.

Thanks for your help!

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