I tried to move a ZD and a few APs from one subnet to the next a few weeks ago (before reading this post) and got into so much trouble that it ended up easier to reset the APs and reconfigure them... Can I check that the proper process (for a ZD1200 v9.13+ 3x R500 APs, moving from 192.168.0.0 to 192.168.100.0, on the same VLAN) is:
1. on the ZD, configure Limited ZD Discovery as above: primary = 192.168.0.{zd} and secondary = 192.168.0.{zd}
2. give it a few minutes for replication
3. change the IP address of the ZD to 192.168.100.{zd}
4. give it a few more minutes for the APs to find the ZD
5. change the IP address of each AP to 192.168.100.{ap1,ap2,ap3}
6. give it a few more minutes for the APs to reconfigure themselves with the new IP's
7. either remove the Limited ZD Discovery setting, or simply have primary = 192.168.100.{zd}