VMware NSX
Before decommissioning, It is recommended to disassociate the reference object and compute manager from NSX prior to decommissioning, since NSX maintains its inventory and object relationships through registered Compute Managers, any association can result in stale cluster or host references remaining in the NSX inventory even after transport nodes are removed from vCenter/SDDC.
To resolve this issue and clear the orphaned inventory, you must manually remove the stale Compute Manager from NSX.
Log in to the NSX Manager UI.
Navigate to System > Fabric > Compute Managers.
Identify the Compute Manager (vCenter Server) that was associated with the decommissioned workload domain.
Select the entry and click Delete.
Confirm the deletion when prompted.