Unexpected issue

I have installed several Shelly 1PM to control my outdoor lamps. After one week without any problems one of the devices suddenly stopped working. It looks normal in the app, the device is reacting when using the ON/OFF in the app and I also see that there is power on the Outlet. I only use it as a ON/OFF for scheduling so I don't have any switch connected. I have tried another 1PM with the same result, the lamps just doesn't turn on. And yes, the lamps are working fine when I disconnect the 1PM.

Any suggestions what could be wrong?

Yes, of course, I add a pic of the wiring. Unfortunately, I don't have a voltage meter so I can't give you any figures here. It is weird that it actually worked fine for a week. And as I mentioned, I have tried several 1PMs with the same result so it can't be a faulty device.

Yeah, you might be right. I have ordered some new gen3 products. Hopefully that will solve it.