Azure WAF configurations attached to Application Gateways can persist after their backend pool resources have been removed — often during environment reconfiguration or application decommissioning. In these cases, the WAF is no longer serving any functional purpose but continues to incur fixed hourly costs. Because no traffic is routed and no applications are protected, the WAF is effectively inactive. These orphaned WAFs are easy to overlook without regular cleanup processes and can quietly accumulate unnecessary charges over time.