The API request: GET https://{mgrIP}/policy/api/v1/infra/segments may NOT list these segments, but they are listed when run as: GET https://{mgrIP}/policy/api/v1/infra/segments?include_mark_for_delete_objects=true
When an NSX segment is marked for deletion, the NSX Management Plane and Central Control Plane begin unbinding the logical resources associated with that segment.
Even if the segment remains visible in the UI because it is "stuck" (often due to active port attachments), the underlying Virtual Network Identifier (VNI) is often unassigned or placed in a "ghosted" state (VNI -1). While some VMs may maintain connectivity temporarily using stale cached entries on the host, any event that requires a new control plane look-up (such as a VM power event or a host-level management trigger) will result in the controller dropping the traffic because it no longer recognizes the segment as a valid forwarding target.
An NSX segment in a "Marked for Delete" state is not a valid object for hosting production traffic. To restore stability: