After 18 months, Telsa and Landis+Gyr, the meter manufacturers, have agreed a solution (single phase but the meters are dual single/ 3phase). My electricity supplier, EDF, have replaced my L&G E470 Type 5424 meter with the olderType 5394 version. Result Kama! I have to say that once an EDF man ager found the same problem they were really helpful. It's a problem of interaction between the meter and Gateway.The newer meters suffer intererence, the older ones don't. The L+G E470 Type 5394, shown below, works correctly with the gateway, the more recent Type 5424,shown second, adds 3kWh per day phantom consumption in my case. Octopus should know, they were in on the investigation.