Hello. I walked into a situation that has 4 Ruckus R500 access points. There are 2 SSID's being broadcast, both on VLAN1. One is a private network that has no restrictions other than WPA2 password, the other one has the additional 2 checkboxes set to enable guest isolation (under advanced settings, then on the other tab) and also has a guest isolation whitelist enabled.
The whitelist initially had 1 entry which was the mac address and IP of the gateway. This works, and allows internet access. Removing this makes internet access/dhcp/dns stop working on the guest network (which is not an issue, leaving this enabled)
I have a google chromecast on the normal SSID that has no restrictions. People on that same network can use it just fine. I added it to the same client isolation whitelist though, and cannot ping it / see it / cast to it consistently. The odd thing is that I could very sporadically see/ping it, which I believe to be just a fluke as it only lasted around 30 seconds.
I have updated to the most current firmware as they were 2 years out of date.