@Pocket-Sevens 

Which mode are you currently running the Deco in?

@Tony Hi Tony.  I'm using the Deco in router mode.

@Pocket-Sevens 

The Deco in router mode is likely why you do not see the option. If you were to switch the router to AP Mode that option should then come up. In router mode, it should isolate by default (isolate via VLAN 591).

@Tony Hi Tony.  Thanks for your reply.  It sounds like Guest Network isolation is working by default in router mode.  That is good. 

Two quick questions:

1. If I switched to AP mode, it sounds like there's a switch to have the guest network isolated.  Correct?  Is that also VLAN 591?
2. Will guest network isolation work in AP mode if I have a WiFi backhaul?

Thank you so much for all of your help.  I truly appreciate it.

@Pocket-Sevens 

1. Yes, it would be the same VLAN

2. Yes, it would work in both wired and wireless backhaul.

@Tony Hi Tony.  Thank you so much for your help on this.  I noticed that, if I join the main network, I can ping other devices on the main network but not on the guest network.  If I'm on the guets network, I can't ping any device on either network.

I've also put the Deco in AP mode to have a separate router handle the router functions.  But, I've noticed that all devices use the same DHCP pool from the main network.  The DHCP pool I assigned for VLAN 591 isn't seeing any devices.  Mind you, I'm using a WiFi backhaul and I think I read somewhere that VLAN for WiFi backhaul may be working in a future firmware release.  Anyway, I've got things working now and really appreciate your help on this matter.

Thank you. 

@Pocket-Sevens  I Did the update firmware and I had to call the vendor Amazon for them to send me a new set of DECO S4 pack of 3 the main Deco crashed and all my network went down I got the new today but I am afraid to update the firmware please advise?

@Jsam1212 Hi there.  How did you do the firmware update?  Did you use the Deco app?  Or did you try to update the Deco through the web page?