The expunge.delay and expunge.interval are related to how long your destroyed VMs will be kept until they are actually expunged. During this period of time you can still recover your destroyed VM. By default these parameters are setup to 86400 seconds (24 hours). You won't see the direct IPs number changing until the expunge is done. Personally I've changed these values to 5 minutes.

Daniel

Daniel's response is spot on. Good stuff.

Request to the original poster to please confirm if the issue was resolved with this recommendation.