I registered one domain on the Dynamic DNS setting page by default option (Service Provider : TP-Link)

That domain was immediately related to my public IP address, this part works well.

But, actually I don't need this function, I just try this out of curiosity.

When I try to disable this TP-Link Dynamic DNS function, it doesn't work.

I unbound and deleted that domain on the setting page, then logged out and unbound this router with my TP-Link ID, but that domain still being resolved to my public IP.

After that, I re-bound the domain, Unbound and deleted it one more time, then reset (Restore all settings to default values) the router without login my TP-Link ID, I tried to connect to another network with a new public IP, I cannot believe that domain(on DNS severs) still being updated to the new public IP after I connected to the new Internet.

It seems the Dynamic DNS function is automatically associated by a hidden identification which cannot be reset in my router.

I really think TP-Link should pay attention on this, maybe this just a setting or reset bug, but it somehow make me thinking this router is doing something which is not supposed to do.