If you experience a timeout error message saying "Home could not connect to this accessory" when you add a HomeKit accessory, try:

1. Standard procedure: Confirm that your iOS device is connected to the IoT 2.4 Ghz wifi network, put your accessories in the setup / pairing mode
2. Go to the iOS Wi-Fi settings and select accessories under Devices (under the Select a Network section) and follow the prompt
3. When the accessory is connected to the wifi network, go to either the Home app or the app's app and add accessories to HomeKit (in this step, in both cases, the barcode scans the work for me and does not manually enter the number)

& # X200B;

After a cascade and coinciding series of issues with an Aqara hub and a Vocolinc power strip that ended up in me, they both reset them without frustration, I became quite stuck and tried to add them to HomeKit again. No matter what I tried, I kept getting the message "couldn't connect to this accessory". Many hours later I finally stumbled this way to save the wifi network settings to the accessory first and then add accessories to HomeKit afterwards. This got both the hub and the strip up and running immediately.

& # X200B;

I'm on iOS 12.1.1 so it may well have been ironed out in newer versions but just to leave this tip here if it helps anyone ...