DHCP keeps granting recently freed IP leases

[#1]

Hi experts,

I'm facing some issues with IP Theft under Cisco WLAN (Catalyst 9800) where some devices are receiving an IP lease from Infoblox which was assigned to a device that has been recently connected to the WLAN but it's not connected anymore.

Cisco C9800 has a customizable timeout to clear all information from previously connected devices, and if the IP address granted to a new devices matches that in DB from a previous device within that time (now I have it configured for 30 minutes following Cisco's BP), the device is not allowed to connect.

The problem is that when I check Infoblox for the DHCP on that range, there are some Free leases that has a MAC already assigned, and there are also some Free IP leases.

My questions, is there any way to tell Infoblox not to re-use an IP lease for a given time? Or to tell Infoblox to use Free IP addresses in a FIFO-like fashion and not something close to a LIFO-like fashion? Is there any way to tell Infoblox to clear the previosly assigned in a sorter time?

Regards.