@TazMie 

Hi, which password did you refer to?

and may I know the model number of your TP-Link device?

PS: the default Wi-Fi password is 8 digits on the back label;

the default log-in password for the web management page is admin;

@TazMie 

Hi,

I have 3 TL-WPA4220 and I can only change the wifi network name of one of them. The other two ask me for a password that I don't know. (admin) the default password is not working. I have tried to reset them several times but it always asks for the password.

How to do?

@luca.caizzi 

Hi, Which 3 of the PLCs are TL-WPA4220?

On the attached picture, there seems to be only one wireless powerline adapter(the one on the left # Device-0CC6) and the other 3 are all detected as wired powerline adapters?

Would it be kind for you to record a video clip about the utility that keeps asking for passwords?

By the way, what are the hardware version of your TL-WPA4220s?—you could see the hardware version on the back label.