AP's not picking up IP config after subnet change

[DaveNet]

My organisation is migrating approx 400 sites to SD-WAN, with that comes IP change. During the last 3 migrations, some of the MR18 and MR33 AP's have simply not picked up the new IP information specified, either by DHCP or Static config. Meraki dashboard still displays the old config and associated switch ports are showing old IP address. 

This has never been an issue previously, the connected switches are running 15.21.1 and the MR33 is running 28.7.1 and MR18 running 26.8.3. 

Has anybody come across this before? We cannot even connect to the AP because it's either not broadcasting the SSID's, or the Corp SSID uses 802.1x so we cannot connect without it's IP address. 

[alemabrahao]

Do you have VLAN tag configured on the Access points? Have you tried cleaning ARP table or DHCP lease? Have you opened a support case?

[DaveNet]

Yes, support case has been opened awaiting reply 

We have the native vlan configured on associated switch ports for the AP to pick up it's IP. APs are tagging the SSIDs with associated vlan on the trunk.

An issue is we are not responsible for the management of the Routers at these sites, we have a contract with an ISP to manage these and we have very limited access to Layer 3.

[PhilipDAth]

What I like to do when changing IP address schemes is reboot all the switches.  This forces everything attached to send new DHCP requests.