Your setup looks correct. You also need to select the Director Camera Root gameobject, and in the Director Camera inspector, set the Post Processing Volume Layer to the same layer as your global Post Processing Volume:
[attachment file=”DirectorPostProcessSelect.png”]
Let me know if this works for you. I would also advise to please try updating to the latest version of Slate?
Does your project use URP or HDRP, or does it use the standard render pipeline by the way?