@Adon 

Hi, please check if other settings like the WiFi name and password have been changed to the default one or not, which could confirm if the device has been reset successfully.

You could also try your previous login password to see if it still works. If not, please try resettings the device again by holding reset hole until you see “Power Off” on the screen, then TP-Link Logo, “Restoring” and “Succeed” will appear on the screen successively, which means the factory reset really works.