Sonicwall routing & UniFi Cloud Key

I am setting up a Sonicwall TZ400 and 2 UniFi switches for a client.  Swtich A will be for data and Switch B will be for IP Phones.

X0 is a LAN port setup as 192.168.5.1 / 255.255.255.0 - DATA - Switch A
X1 goes to the WAN (FIOS)
X2 is a LAN port setup as 192.168.6.1/ 255.255.255.0 - IP Phones - Switch B

X0 and X2 both have DHCP setup, 192.168.5.100 - 254  (X0)  &  192.168.6.100 - 254 (X2)

I need to make sure all ports are open on the LANS and that traffic from X0 & X2 can talk to each other in both directions.  Also, the networks need to be able to talk to for the UniFi Cloud Key to work.  The UniFi Cloud Key is a Layer 2 device and it is used to remotely administer the switches and wireless access points.

The UniFi Cloud Key is plugged into the switch connected to X0 (Data).

Currently the Cloud Key can see the switch and access points on X0 (Data), but it can't see the switch on X2 (IP Phones).  Also, I believe it uses port 8080 to talk to all UniFi devices.

Do I need to create any routing entries for X0 and X2 to talk to each other?   Is it ok that X0 & X2 have the same subnet?  Should X2 use X0's gateway or inherit it from the sonicwall?

Thanks in advance for your time.