@SimonC. Good job sticking with this, it must be frustrating! I have the older HS100 & HS110 and neither seem to have the issue, so it's not a general problem. Seems like it really can only be a few...

@WhiteRedHat Ok, that makes more sense. If you can unplug the KP303 and your network comes back up after a few minutes, then it's certainly a bug in the KP303 firmware - probably ARP flooding. If the...

@seynom I'm going to raise my guess to 99.999% it's a wiring problem :). The likelyhood of 3 separate devices having the same problem is almost 0... For sure the electrician didn't wire them in...

@seynom Sounds more like it wasn't wired properly or the dimmer switches were broken (less likely). The switches draw maybe 2-3W each maximum, adding 150W shouldn't come close to the 1600W needed to...

Your router would not come back up even if power cycled after unplugging the LP303? Try turning off the phone with the Kasa app to be 100% sure. If it still doesn't come back up something else wrong...

@TP-Link You've answered in an earlier post that you plan to roll this fix out to ALL of the devices. So you're going to need to ramp up this process for everything - is that your plan?