WAN Port not updating new IP address.

Question

I have a Sophos XG 125 Firewall and recently after updating the latest firmware, I'm having an issue with WAN port of firewall. 
 The firewall's WAN port does not update the IP address automatically. I have to unbind the port and bind the port again to update the IP address at WAN port. 
 For instance, I connect firewall with "A" connection which has 10.200.200.14 IP address in DHCP mode. It will get this IP and works fine. But when I unplug the cable from WAN port. I can still Ping the WAN IP 10.200.200.14 even if the port shows unplugged. 
 Secondly, when I connect firewall with "B" connection with 10.200.200.50 IP address in DHCP mode. The firewall does not update the WAN IP after that, and I cannot ping the new IP but still can ping old IP of connection "A". 
 Only way to update the WAN IP is turning off WAN port and turning on back again. 
 Is anyone else having this problem?

Vishal_R · Answer

Hi Gary Singh : Thank you for reaching out to the Sophos community, currently DHCP renew request (over WAN) will only get generated once the active leased time gets expired or one will save or update the respective WAN interface manually, and due to this when you update or save WAN Port you are getting new IP of your new connection B via DHCP as it will generate DHCP fresh/renew request. In past, such a discussion happened on the below community thread - you may refer to old conversation to get more information. The manual renewal on DHCP disconnection or unplugged is currently a feature request ( SFSW-I-1139 ) and plan in the future road map: community.sophos.com/.../505608 Regarding when you unplug the interface and still you are able to PING the old IP of connection, with status unplugged are you able to see the old leased IP on the WAN interface as is? if yes then due to that still XG route table (#route-n) has a route for it and due to that it is giving you a PING reply.