RBR50 Guest is NOT enabled but still showing as an option in list of available networks

[Elisern]

I got notified by my internet provider that I was nearing my data limit and identified unknown traffic.  

I have always had guest wifi disabled.

Changed my wifi password and to my amazement periodically, not all the time, am noticing that phone is displaying an available guest option for my network.

Have checked Orbi and find guest network is still disabled.  Have rebooted system more than once, but still periodically see guest network offered.

Why is it there when I have guest network disabled?  ...and the one displaying has no lock on it.  No wonder people are jumping on.

How do I turn it off, and keep it off? 

Of course this system is well over 90 days old, and even though it was around $400 plus, they still don't offer 'complimentary customer support'

Thanks in advance for the help.

[CrimpOn]

It might be worth a few minutes to verify that this open guest WiFi network is from your Orbi.

My plan would be to (a) assign a unique name to my Orbi guest WiFi, such as "AliBaba", and put a password on it, perhaps "OpenSeseme".

Then, disable guest WiFi and observe the name of any open WiFi network on my phone.

Is it "AliBaba", or is it a different name (SSID)?