I think you have to broadcast the ssid to get it to work properly

you could use the guest function of the router so you don't have to change the main radio settings

and even though it is static IP: add a DHCP reservation in the router for the T3x

I have a T3x using wifi and zigbee:
there is a 7-10 second delay from wakeup until wifi light comes on

zigbee handles most of the operations: wifi is for firmware updates;
zigbee is much better...