@Daniel6 

A major issue is the switch not responding to any physical action. If the wireless connection was the only issue, pressing it would still work. If all wires were double checked and look to be normal the switch itself may have malfunctioned. You could possily try moving it to another outlet to verify the issue follow the switch or put back the original switch to make sure the outlet is fine. 

If it turns out to be the switch it would be best to get a hold of our home support: https://www.tp-link.com/us/support/contact-technical-support/#LiveChat-Support

@Tony

I have exactly the same problem..... it's been working fine since February and yesterday when I went to turn it off (physically) it would not respond. Tried the app, but that made no difference. The lights on the switch (level of dimming indicators) responded correctly, but the light just stayed on! I removed the swich from the app and reinstalled it, but again, no difference.... updated the firmware, no difference.

Today I removed the switch and put it in the place of another 220 that works fine and again, the switch didn't work..... just stayed on.

So, I guess that the switch has an internal problem and needs to be replaced.

Not too impressed at this stage!

Same here. Never worked, and it's the second one I purchase. The first did absolutely nothing, like if it was not even connected (previous ordinary dimmer was connected the same way and worked fine). The second one is always stuck on even when I turn it off by pressing manually the switch or with the application. So far I had problems with 3 devices out of 7 total.