Updated
Quick fix
Many smart devices only work on 2.4 GHz Wi-Fi, need a strong signal during setup and may not accept some special characters in passwords. Set up close to the router, use the maker’s app and reset the device if a previous setup failed.
Step by step
Check the Wi-Fi band
Many smart plugs, bulbs and cameras only support 2.4 GHz. If your router combines bands under one name, setup may fail; your router may let you turn on a separate 2.4 GHz network temporarily.
Set up near the router
Do the setup close to the router, then move the device to its final spot.
Double-check the password
Wi-Fi passwords are case-sensitive. Some devices have trouble with very long passwords or special characters.
Use the maker’s app
Update the app, allow location and local network permissions on your phone (they’re often needed to find the device), and follow the in-app steps.
Reset the device
If an earlier setup failed, reset the device using the button or sequence in its manual and start again.
Check guest or business networks
Guest Wi-Fi and some business networks block devices from talking to each other. Use the main network or a network made for smart devices.