Answer
Quick Reports need their own separate grant beyond the projection/entity access — the permission set that actually enables running SQL-based quick reports is FND_QUICK_REPORTS (or, more narrowly, the CEN_QUI_REP_READ entity/projection action for QuickReportHandling). Since FND_QUICK_REPORTS itself grants broader access than just quick reports, consider copying it into a scoped functional role with only the quick-report-relevant grants retained, rather than assigning the full built-in permission set to every user.