AWS policy for step functions: some actions, resources, or conditions do not provide permissions

I am editing a policy document to allow Lambda sending TaskSuccess to a step function. A statement below, although granting the right permissions, causes the warning to appear. I need advice if this is a "false positive" warning, or I am actually misconfiguring a policy document.

Statement that causes the warning:

    {
      "Sid": "VisualEditor2",
      "Effect": "Allow",
      "Action": [
        "states:SendTaskSuccess",
        "states:SendTaskFailure"
      ],
      "Resource": "arn:aws:states:eu-central-1:xxxxxxxxxxxx:stateMachine:sample-waiting-step-machine"
    }

Warning text:

This policy defines some actions, resources, or conditions 
that do not provide permissions. To grant access, policies 
must have an action that has an applicable resource or condition. 
For details, choose Show remaining.

Once I tick "show remaining services", the following warning shows up in the table