The Spiral\RoadRunner\KeyValue\Cache class will set the value regardless of whether it exists or not - it always resolves the lock, you need to check for the existence of the key using the has method

Author: xav-developer

src/Cache/RoadRunnerLock.php

@@ -25,6 +25,10 @@ public function __construct(
      */
     public function acquire()
     {
+        if ($this->storage->has($this->name)) {
+            return false;
+        }
+
         return $this->storage->set(
             $this->name,
             $this->owner,