I'm running a few CPL600 adapters in the house, one of which goes to a home office in the spare room. It connects a printer and it has been working fine for months. Yesterday I plugged in an Amazon Echo Flex in the hallway and this morning I found that the CPL in the spare room had lost connection. I checked it in another socket (where it worked) and checked another CPL (which worked in other sockets but not the one in the spare room) and decided the only change to the installation was the Echo Flex. After unplugging the Flex the CPL immediately reconnected. Plugging in the Flex resulted in the CPL losing connection right away. I plugged the Flex into a different socket and everything was working as expected. The socket in question is used to run the vacuum cleaner occasionally and although I have not checked I do not recall losing access to the printer before. I have two questions:

1. What is the possible cause of the Flex interfering with CPL communications? The mains side of the Flex is basically a 12v transformer and it should not interfere with CPL communications.
2. What can I do to prevent this from happening? (I have a feeling that whatever the answer to question 1 is, it would lead to the answer to question 2).