fix #879

src/Form/Field/CanCascadeFields.php

@@ -109,7 +109,7 @@ trait CanCascadeFields
             'has' => '8',
         ];
 
-        return sprintf('cascade-%s-%s-%s', $this->getElementClassString(), $value, $map[$operator]);
+        return sprintf('cascade-%s-%s-%s', str_replace(' ', '-', $this->getElementClassString()), $value, $map[$operator]);
     }
 
     protected function addCascadeScript()