DEVOLO malfunction

So it is so I have such a d-lan plug in the socket in my room and everything works perfectly in my room but in the room right next to it the signal is so bad that all devices such as ps4 constantly disconnect. I was told by the landlord that there are water pipes in the walls of this room. Could this be the cause of poor reception? In addition, when I try to connect a second devolo connector in the other room, the password of this connector does not work and therefore can't connect to it, please help quickly!

Nonsense is not due to the water pipes. It is also due to the circuit, in the living room I have poor connection with "Internet via the socket". Because they are on a different circle.

all other rooms flawless.

have now switched back to Wi-Fi works perfectly.