2898917 - My Inbox application hangs during Purchase Requisition approval steps

• My Inbox application is not loading Purchase Requisition flexible workflow workitems properly (endless load), therefore the approval process can't executed.
  AND In transaction /IWFND/ERROR_LOG and in browser console, the following error occurring: "Invalid URI segment".

OR

• Purchase requisition workitem details are empty in My Inbox detailed screen. 

• SAP S/4HANA
• Task Gateway
• My Inbox Fiori application

C_PURREQUISITIONITEM_FS_SRV, /IWFND/CM_CONSUMER122, WS00800157, TS00800547, WS00800173, TS00800548, WS02000458, TS02000702, WS02000471, TS02000714, WS02000434, TS02000677, console log  sap/opu/odata/IWFND/CATALOGSERVICE;v=2/Annotations(TechnicalName='C_PURREQUISITIONITEM_FS_ANNO_MDL',Version='0001'), flexible workflow objects load hanging, visualization type, service=/sap/opu/odata/sap/C_PURREQUISITIONITEM_FS_SRV, C_PurRequisitionItemFs, PurchaseRequisition, TASKPROCESSING , KBA , MM-PUR-GF-WOF , Workflow , CA-INB-FIO , Fiori UI for My Inbox Application , OPU-BSE-WFM , Gateway Business Workflow Enablement , MM-FIO-PUR-REQ-SSP , Fiori UI for Self Service Procurement , OPU-BSC-TGW , Task Gateway , Problem