DHCP Release Message (proposal)
pfSense does not send DHCP release message to the DHCP server to actually release the address.
pfSense merely brings it down locally. Doesn't even remove the address from it's leases database. So renewal will request the same address again.
Status / Interfaces - Relinquish DHCP Lease
DHCP Release Incomplete (Status: Interfaces)
DHCP Release does not work correctly
Releasing DHCP on WAN interface should send a release
DHCP release does not send proper DHCP Release packet to DHCP server
duplicate of #4209