@manin 

From the picture attached, the powerline link rate between the 2 adapters are extremly slow, generally speaking, the speed is 30%-40% of the powerline link rate, combined with the obstacles, the actual speed will be slower. Try to change another outlets to plug the 2 adapters and plug them into the wall sockets directly.

After that, verify the powerline link rate and the actual speed you can get. 

Besides, you can plug them into the same room to test their performance.

Good day. 

@manin 

The speed on the utility is the powerline link speed, which is related to the powerline environment and some other obstacles. 

It is suggested to change another sockets to plug them. 

Besides, per I said before, the actual speed is about 30-40% of the powerline link speed. 

Good day.