how to fix teredo error "Client on managed network"

Just to clarify these are my Teredo paramaters:

Type : enterpriseclient

Server Name : win1910.ipv6.microsoft.com.

Client Refresh Interval : 20 seconds

Client Port : 3544

State : qualified

Client Type : teredo host-specific relay

Network : managed

NAT : cone

NAT Special Behaviour : UPNP: Yes, PortPreserving: Yes

Teredo is a networking protocol that’s used to establish secure communications between clients and servers, and to facilitate connectivity between devices behind routers that use network address translation
(NAT).

Failure to obtain a Teredo IP address can occur when there’s an issue with your Teredo adapter, when a device on your network is blocking the Teredo protocol. Without a Teredo IP address, you’ll be
unable to use party chat or do multiplayer gaming on Xbox Live.

Check to see if Teredo connectivity is blocked when a VPN client is connected, or while a VPN network adapter is installed

Some VPN clients will disable Teredo connectivity while the VPN client is connected, and some VPN clients that install a network adapter that will disable Teredo until the VPN adapter is removed. If you’ve
installed a VPN client and Teredo is still disabled even while the VPN client is disconnected, check to see if you have a network adapter named
TAP-Windows Adapter V9 installed:

1. Right-click the Start icon, and then select Device Manager.
   
2. Select View > Show Hidden Devices.
3. Select Network Adapters.
4. Identify any adapters that have a name like TAP-Windows Adapter V9. Right-click the adapter name, and then select
   Uninstall.
   Note While uninstalling the VPN network adapter should unblock Teredo connectivity, this will also likely cause issues with the VPN client software. If you still require VPN functionality along with Teredo support, refer to the support documentation
   for the VPN client.
   

Hi NathanielPritchard-Jones! My name is Ricardo an independent advisor ready to help you with this situation!

Some VPN clients will disable Teredo connectivity while the VPN client is connected, and some VPN clients that install a network adapter that will disable Teredo until the VPN adapter is removed. If you’ve installed a VPN client and Teredo is still disabled even while the VPN client is disconnected, check to see if you have a network adapter named TAP-Windows Adapter V9 installed:

Right-click the Start button, and then select Device Manager.

Select View > Show Hidden Devices.

Select Network Adapters.

Identify any adapters that have a name like TAP-Windows Adapter V9. Right-click the adapter name, and then select Uninstall.

***Note While uninstalling the VPN network adapter should unblock Teredo connectivity, this will also likely cause issues with the VPN client software. If you still require VPN functionality along with Teredo support, refer to the support documentation for the VPN client.

Restart your PC.

Well for any other people looking for a solution, this is it:

https://www.reddit.com/r/Windows10/comments/m1xgzt/teredo_is_unable_to_qualify_client_is_in_a/

Let me just add for any developers: Teredo is stupid and riddled with issues.

I'm Samy an independent advisor. Welcome to the community. How are you?

Your problem was solved with these instructions that are in the link you mentioned, mate?