Object Cache “Connection Test: Failed”

Hi, I have multiple sites running on seperate shared hosting accounts on Stablehost which runs LiteSpeed Servers.

I had the Litespeed-Cache WP plugin + Object Cache (Memcached) working for a few months without issues, and this week I noticed Memcached can’t connect.

PHP Version: 8.1.22
Server API: LiteSpeed V8.1 Cloudlinux 1.3
Memcached Version: 3.1.5
libmemcached version: 1.0.18

Status
Memcached Extension: Enabled
Redis Extension: Disabled
Connection Test: Failed (Learn More)

Host: localhost
Port: 11211

I went to Learn More and setup the Test file to connect to Memcached.

<?php
error_reporting(E_ALL);
ini_set('display_errors', 1);

$m = new Memcached;
$m->addServer('localhost', 11211);
print_r($m->getServerList());

echo '<hr>';

$key = "test_key";
$value = "Hello, Memcached!";
$expiration = 3600;

try {
    // Set value:
    $m->set($key, $value, $expiration);
    
    // Read value:
    if ($m->get($key)) {
        echo "Value successfully set in Memcached.";
    } else {
        echo "Failed to set value in Memcached.";
    }
} catch (Exception $e) {
    echo "An error occurred: " . $e->getMessage();
}

Results:

Array ( [0] => Array ( [host] => localhost [port] => 11211 [type] => TCP ) )
Failed to set value in Memcached.

• Connection seems to be established and returns a list that contains 1 server.
• But when I expanded script with set/get, it fails to return the value, so seems that value isn’t being set.
• PHP doesn’t throw any errors.

I contacted Stablehost and asked them to restart the Memcached server, to which they told me (1) they can’t restart Memcached on a shared host, and (2) to contact the plugin creator.

I said: that doesn’t make sense, because even without the plugin, I can’t connect to Memcached. To which they wasted my time by making me wait an hour saying “I’m looking into it”, and when I left, told me to contact the plugin creator.

Do you have any idea what could be wrong?

To me looks like Memcached is blocked/frozen and needs a restart, but I wanted to double-check with you.

This isn’t even just one website, (1) it’s all my WordPress websites on this one shared account, and (2) I also manage a second account on Stablehost in WordPress + LiteSpeed-Cache and it has the same issue now. So it’s a cross-account problem at this point.

It’s a Stablehost server issue, right?

I tried using Redis and I’m getting the same issue there as well (I know it says Disabled here, but I only Enable either-or, turned it off after it wasn’t working).