https://userapps.support.sap.com/sap/support/knowledge/en/3469349
3469349 - The "Event Reason" field is greyed out/uneditable - Onboarding | SAP Knowledge Base...
The Event Reason field is greyed out/uneditable in the Review New Hire Data step. Image/data in this KBA is from SAP internal systems, sample data, or demo...