For BIM 360 projects the [ProjectFolder] keyword can not be used in post action file copy because it is a BIM360 path.
Create a new field in the New Project "Local Network Path" used for artifacts.
Then it can be used in Post action tasks in folder paths.
Example path for Local network project - [ProjectFolder]\..\..\CURRENT SET\PDF
Example path for BIM360 project - [LocalNetworkPath]\..\..\CURRENT SET\PDF