strange DHCP behaviour

[Tony van der Hoff <tony@vanderhoff.org>]

Hi, I havea laptop running fully up to date Stretch with NetworkManager,
set to use DH|Cp via wireless.

The DHCP server is another Stretch system, with the stanzas
host tony-lt {
	hardware ethernet 0c:60:76:6c:e6:6f;
	fixed-address 192.168.1.199;
	}
subnet 192.168.1.0 netmask 255.255.255.0
	{
        range 192.168.1.200 192.168.1.254;
        option routers 192.168.1.10;
	}

That MAC is correct for the laptop.

I an expecting to see 192.168.1.199 as the laptop address, but no, if a
gives:
wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP
group default qlen 1000
    link/ether 0c:60:76:6c:e6:6f brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.253/24 brd 192.168.1.255 scope global dynamic wlan0
       valid_lft 479sec preferred_lft 479sec

Finally, the server shows:
Oct 23 14:23:38 routerpi dhcpd[1068]: DHCPREQUEST for 192.168.1.253 from
0c:60:76:6c:e6:6f (tony-lt) via eth0
Oct 23 14:23:38 routerpi dhcpd[1068]: DHCPACK on 192.168.1.253 to
0c:60:76:6c:e6:6f (tony-lt) via eth0
Oct 23 14:23:53 routerpi dhcpd[1068]: reuse_lease: lease age 15 (secs)
under 25% threshold, reply with unaltered, existing lease for 192.168.1.253
Oct 23 14:23:53 routerpi dhcpd[1068]: DHCPREQUEST for 192.168.1.253 from
0c:60:76:6c:e6:6f (tony-lt) via eth0
Oct 23 14:23:53 routerpi dhcpd[1068]: DHCPACK on 192.168.1.253 to
0c:60:76:6c:e6:6f (tony-lt) via eth0

So, my question: why is the server handing out .253, when it is
configured to provide .199?
What is this 'reuse-lease' all about?

I've tried 'dhclient -r wlan 0; dhclient -v wlan0' on the laptop, to no
avail.

Any suggestions, please?
-- 
Tony van der Hoff  | mailto:tony@vanderhoff.org
Ariège, France     |