https://userapps.support.sap.com/sap/support/knowledge/en/3067986
3067986 - Front-end printing is not supported in Fiori reuse UI and SAPGUI with SAP S/4HANA output...
You are using SAP S/4HANA output control as your output solution. Front-end printing via the spool system is not supported when using Fiori apps or SAPGUI.