@JonHM Thats horrendous.

Yes, it would have failed regardless.

@YorkshireKasa Its a capacitor failing over time. This causes a loss of a stable DC supply to the relay circuiit causing it to rapidly switch on and off.

@YorkshireKasa I changed to INNR and Frient Zigbee switches instead. The TP Links tend to fail after two years, after the warranty has expired sadly.

@thewatcher No they are not since they are outside of warranty. But since they are failing in a predictable manner time after time, the design is clearly very poor and I will never byy a smart pluig...

It doesnt matter if the device only cost 10 bucks, the issue is the manner in which it fails and the damage it can cause to equipment connected to it. Its failure mode is a design choice.