Hi,

Cause the PA9020P kit works fine when they are in the rooms fed by CU A, the device itself should be working fine, the powerline environment, instead, has some changes. 

Meanwhile, cause the powerline environment is invisible, it is hard to say what changes has happened. 

First, you can pair them, and then try to relocate them, if the powerline light (house light) goes off, change another power socket to plug it. 

Meanwhile, you can get a computer(Windows or Mac) to use the tpPLC utility to update the firmware, disable power saving mode and lower PLC-to-VDSL interference Mode.

Note: You can click them to get detailed instruction. 

Besides, cause the second powerline network works fine now, you can exchange their locations or test whether the second powerline network works fine with them replaced 9020P.

May it help and have a nice day. 

Hi,

The tpPLC utility is available for windows and Mac computer only. If possible, it is suggested to get one computer and use the utility to adjust some settings.

Meanwhile, it is glad to hear that they works in their original positions, that means the powerline adapters work properly.

You can take more time to test its performance. 

Any updates, just let us know.