Hi, I've bought a L510B and it omits a high pitched sound which is audible up to 10 feet away. The sound is present even when the bulb is off so I guess it is related to the wifi components. I'm just

I've just bought 4x1 and 1x1 Tapo L510b smart bulbs I have set up 4 of the 5 successfully. But 1 of them lit up and flashed 3 times but refused to pair now it's not possible to even turn it on. I have