@Mrpoune Hello, 

Sorry for the delayed reply, may I have a link of the lamp connected to KP400?

If you tried  different home appliances or a different lamp, could it get power as well, many thanks. 

Please manually switch off KP400, press the control button to turn it off, is it the same case? 

@Mrpoune Hello, 

Thank you for your reply. May I know the model of the Led lights or the purchase link of the Led lights?

If you try a different light fixture or lamp and see if other lamps do the same?  Does this happen to both sockets of Kp400?

May I know where did you plug the KP400, can I have a photo showing how did you place the KP400 if possible, thank you. 

As this case is a bit special we'd like to have a specialist  to follow up your case via email, please check your inbox later, thank you.