Something strange with GET /task/{id}/localVariables

Need help with localVariable.
I have usertask in my camunda modeler.I create input variable on task. In cockpit i see than variable is in task scope.But API GET /task/{id}/localVariables return null…(task is open now)
If i use GET /task/{id}/variables i see my task variable+ other process variable. I need to get only localVariable task. Whats wrong with me?