Do I need to restart DHCP service before static mappings are "forgotten"?

[Asperamanca]

I was testing a network connection issue, and wanted to temporarily remove a device from static IP mapping (DHCPv4).
1) The device was connected and had the static IP address
2) I removed the static mapping on firewall
3) I did "ipconfig release" and "ipconfig renew" on device
4) Firewall DHCP leases shows new IP address in list, but device shows old IP address
5) Rebooted device - still has old IP address
6) Restart all services on Firewall using console - finally, the device gets the new IP address

Is this a known issue with the DHCPv4 service?

EDIT: It works the other way round. If I assign a static IP address and do "ipconfig release" and "ipconfig renew", I immediately get the statically assigned address.