Unleashed Gateway Mode

No, it is not possible to disable DHCP service on Unleashed Gateway AP. It is done this way to avoid config error . For example, in your own DHCP server if you configured gateway IP to be something other Gateway AP's LAN interface then traffic will not come to Gateway AP. This will certainly cause confusion and network won't work the way it is expected to work. 

Since Gateway AP can provide IP addresses to all clients on the LAN side (both Wired and Wireless) why can't you disable the other DHCP server?

thanks
Nat

The other DHCP server is passing out default domain and a few other options not available in the Unleashed config.

I expected this is likely going to be your reply. I (Product Manager for Unleashed) will take this as a feature request to allow advanced users like you to have the ability to disable it in the future.

 For now, you could keep the Gateway AP off until all the clients get their IP addresses in your training environment and then turn back ON the Gateway AP. Another option is to reduce the DHCP pool size on Gateway AP to just '1' so that client devices will get IP from your DHCP server instead of Gateway AP.

-Nat

If you already have a DHCP service in the network, why do you want to use GW mode on the AP?

I too have this problem.

Workaround:  If the AP is configured as gateway and DHCP server, then under DHCP clients you can see all clients including the wired clients that unfortunately the Unleashed Clients list FAILS to show.

As far as I can see this is a BUG and 2 years since you posted this, it is STILL A BUG.  FIngers crossed Ruckus fixes it.