Unleashed version 126.96.36.199.55 is the current release for your Master AP, and will automatically accept/update APs running previous 188.8.131.52.608 code.https://support.ruckuswireless.com/software/858-unleashed-ap-software-200-1-9-12-55-ga-for-r500
Does a PC connected to your PoE switch obtain an IP from your DHCP server, and can the PC ping your Master AP?
(to confirm your AP has correct netmask and def-gw).
If the PC does pull an IP and can ping your Master AP, I expect the new Unleashed APs should come up and connect successfully.
(If they have Unleashed code. If you converted a ZoneFlex AP to Unleashed, you do need to factory default it afterward to use it.)