@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;

@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.

@luca.caizzi 

Hi, I checked with the engineers, and the password required is the same as the one for web UI log-in.

For the first time, the 4220 has not been fully recognized by the utility(compared with the 2^nd one, the wireless module has not been displayed and only the PLC module is recognized); so even though you put the correct password, there would still be error notice and it is suggested that you could wait for a while and close and restart the utility several times, then put the web UI log-In password again.