This has been reported several times over many years. Every single time the thread has been locked without resolution.

Why does TP-Link force users to use public DNS to access their internal networks? When will you resolve this issue?

This creates a security risk for absolutely zero added value.

https://community.tp-link.com/en/home/forum/topic/544550

https://community.tp-link.com/en/home/forum/topic/509336

https://community.tp-link.com/us/home/forum/topic/615004

https://community.tp-link.com/us/home/forum/topic/252312

https://community.tp-link.com/us/home/forum/topic/589880

https://community.tp-link.com/en/home/forum/topic/604970