You try to use the function 'Delete' in the App Manage Purchase Order but the 'Delete' function is greyed out.
- SAP S/4HANA CLOUD
Reproducing the Issue
Open the App Manage Purchase Order , select one PO
The 'Delete' function that you can see in the App Manage Purchase Order is just available for technical Draft Documents
The Draft documents (PO on Hold) and Real PO documents can´t be deleted with this function.This is the reason why you see the function on grey for POs.
The deletion indication at item level will be available from 1708 in the App Manage Purchase Order--> item navigation --> Edit.
For previous releases you have to access to the real PO through the Advanced Change Purchase Order and set the deletion indicator.
Also you could use the Mass PO to set the deletion Indicator.
FIORI , KBA , MM-FIO-PUR-PO , Fiori UI for Purchase Orders , Problem