Rudder

Inventory is signed with agent key in 3.1 (when node is accepted or key accepted on migrated installation)

Key can have two status:

Undefined => Inventory is pending or Inventory from old migrated node
Certified => Inventory has been accepted or Key accepted on old migrated node

But when a Node is removed, the signature keep being certified so when the node come back (same id, different key) comes back, it breaks

On a side note, check that signature file name is different for a node