"Yor connection to this site is not secure" with Orbi 970

I encountered error "Yor connection to this site is not secure" or can't access to site for some websites while setting up Orbi 970 with default settings. 

After four months and escalating tickets to L2/L3, the issue finally got resolved.  Now my Orbi 970 is faster and as smooth as old reliable rbk853.

I would like to document the error so that this shows up as search in google, as that was how I was trying to find a solution.

I have Orbi RBE973S.  After resetting firmware and installed with default setting, my wifi connection to these three sites would trigger "Yor connection to this site is not secure."  or can't access to some websites.  Weird thing is 2 out of 5 Lenovo laptops work fine.  3 laptops including a new Lenovo P16 would get the same error Yor connection to this site is not secure".  The error "Yor connection to this site is not secure" only happens to main network.  If I switch to guest network, then everything works fine for all laptops.

I had error "Yor connection to this site is not secure." when accessing to these websites.

* www.wsj.com
* www.yahoo.com
* www.netgear.com

In addition, I notice access to website in general even when it works is not smooth as rbk853.  There was some slight delay.  

My internet provider is Frontier fiber.  

After four months of multiple service tickets with Netgear support with L1/L2/L3 support and L2 support even suggested hardware might be faulty, L3 support finally found the root cause of the problem: IPv6 and IPv4 together might cause some sites that are IPv6 capable.

Maybe Netgear firmware does not yet fully support all implementation of IPv6.

My firmware is V9.13.1.2.

The solution as suggested by L3 support is to disable IPv6 in Oracle 970.  

In admin web console, navigate to Advanced > IPv6

under Internet Connection Type, change default setting "Auto Config" to "Disabled"

Click Apply

After this change my Orbi RBE973S is fast and as stable and reliable as old Orbi rbk853.