[14.2.1] DHCP Not responding?

I have a SM that keeps loosing connectivity to cnMaestro when i check it i see it's got a 169 ip address, however the dhcp is showing

Server Not Responding. Default IP in use. Still attempting DHCP...,

It's also acting odd on the session side, i've seen the session drop a few times while i was watching so far its had 50 session reg and rereg in last 5 hours since ap booted...  -74 RSL and 16 CINR so nothing shockingly bad that would cause it to disconnect i would think.

The SM is getting it's dhcp enabled via Radius all my other SM's so far seem to be handling this fine but this ones just acting odd. If i reboot the SM it gets an IP it appears, with a 14 day lease so why would it even be trying to talk to dhcp again if it's got a 14 day lease.

On the radius side it also looks very weird,, appears to be hitting the dhcp server every few seconds. 

Oct 13 15:42:40 wmserver dhcpd: DHCPDISCOVER from 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:42:40 wmserver dhcpd: DHCPOFFER on 192.168.192.151 to 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:42:49 wmserver dhcpd: DHCPDISCOVER from 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:42:49 wmserver dhcpd: DHCPOFFER on 192.168.192.151 to 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:43:06 wmserver dhcpd: DHCPDISCOVER from 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:43:06 wmserver dhcpd: DHCPOFFER on 192.168.192.151 to 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:43:39 wmserver dhcpd: DHCPDISCOVER from 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:43:39 wmserver dhcpd: DHCPOFFER on 192.168.192.151 to 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:44:44 wmserver dhcpd: DHCPDISCOVER from 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:44:45 wmserver dhcpd: DHCPOFFER on 192.168.192.151 to 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:44:45 wmserver dhcpd: DHCPREQUEST for 192.168.192.151 (192.168.192.253) from 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:44:45 wmserver dhcpd: DHCPACK on 192.168.192.151 to 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:44:49 wmserver dhcpd: DHCPREQUEST for 192.168.192.151 (192.168.192.253) from 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:44:49 wmserver dhcpd: DHCPACK on 192.168.192.151 to 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:44:58 wmserver dhcpd: DHCPREQUEST for 192.168.192.151 (192.168.192.253) from 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:44:58 wmserver dhcpd: DHCPACK on 192.168.192.151 to 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:45:14 wmserver dhcpd: DHCPREQUEST for 192.168.192.151 (192.168.192.253) from 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:45:14 wmserver dhcpd: DHCPACK on 192.168.192.151 to 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:45:47 wmserver dhcpd: DHCPREQUEST for 192.168.192.151 (192.168.192.253) from 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:45:47 wmserver dhcpd: DHCPACK on 192.168.192.151 to 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:46:52 wmserver dhcpd: DHCPREQUEST for 192.168.192.151 (192.168.192.253) from 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:46:52 wmserver dhcpd: DHCPACK on 192.168.192.151 to 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:46:55 wmserver dhcpd: DHCPDISCOVER from 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:46:55 wmserver dhcpd: DHCPOFFER on 192.168.192.151 to 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:46:55 wmserver dhcpd: DHCPREQUEST for 192.168.192.151 (192.168.192.253) from 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:46:55 wmserver dhcpd: DHCPACK on 192.168.192.151 to 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:47:53 wmserver dhcpd: DHCPDISCOVER from 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:47:53 wmserver dhcpd: DHCPOFFER on 192.168.192.151 to 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:47:53 wmserver dhcpd: DHCPREQUEST for 192.168.192.151 (192.168.192.253) from 0a:00:3e:xx:xx:xx via eth0:1
Oct 13 15:47:53 wmserver dhcpd: DHCPACK on 192.168.192.151 to 0a:00:3e:xx:xx:xx via eth0:1

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I found the same yesterday trying out the new firmware on AP450i. I got the same message. It was enough to renew the "not yet assigned" DHCP ip address to get effectively an IP address from DHCP server.

ya i did that as well but it lost it again a while later

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As said before I can confirm this DHCP-related issue. We performed some laboratory tests and it came out that devices are not able to negotiate correctly IP address by keeping on "DHCP server is not responding". It seems  (thanks to Wireshark capture) they act for the discovery step but then they don't accept further address offers. However, by clicking on renew button in Home>Network Interface the procedure completes successfully.

did you send the logs into cambium support so hopefully 14.1.3 or whatevers next fixes it