So for an Arahant the avyākata PS cycle is still running. That’s it.
Thank you very much for the explanation!
The kusala-mula PS operates only for Ariyas, starting at the Sotapanna stage. For a normal human (a “worldling”) the akusala-mula PS is always applied. See also https://puredhamma.net/forums/topic/what-is-intention-in-kamma/