IPv4 and IPv6

I don't mean to run this question into the ground but I don't seem to be getting anywhere with Xfinity (no surprises there). They keep telling me that I need to configure the modem but they can't help me because it's not their equipment even tho it's approved by Xfinity for use on the system. The modem is IPv4/IPv6 capable according to Motorola but there are no settings in the Admin page to enable/disable or check as far as IPv4/IPv6 goes.

In the AX4200 Advanced Settings I'v enabled IPv6 and selected DHCP. Auto doesn't seem to work. With IPv6DHCP enabled I seem to get IPv6 addresses but when I check to see if IPv6 is working I get and error message from the link I use (test-IPv6.com) that I am not able to reach the public IPv6 network. I am running the current I get the following message:

"If you strongly believe you have IPv6, but we were unable to detect it: it means one of a couple of things. Either your organization is blocking the use of IPv6 to talk to the outside Internet through network policy; or perhaps what you see with IPv6 on your host is not a global address. Any address starting with "::", "fc", "fd", or "fe" are unable to work with the public IPv6 Internet." The addresses I see all start with "fe".

The Orbi choices I have are: Auto Detect, 6 to 4 Tunnel, Pass Through, Fixed, DHCP, PPoE, Auto Config, and 6rd Tunnel. On my MacBook Pro under IPv6 the choices are Automatically, Manually, or Link-Local Only. Currently I have it set to Automatically.  What is interesting is that the router (Orbi) has an address that starts with fe80::xxxx: and so forth but the IPv6 address starts with 2601: and so on.

The DNS server has the typical 192... address and an IPv6 address that starts with a different 2601: address.

It's not mission critical that I have to use IPv6 it's more of an academic curiosity at this point in time but now it's become a "need to understand" issue.