Hi , I noticed lots of people having smart device connection problems , as did I since I changed to bt smart hub 2 . Numerous calls to bt help , Amazon and Tuya could not sort this.
I eventually sorted this myself and now all is working perfect .
Here is what I did:
1 . Log in to router
2. Turn off 5Ghz and smart set up and save
3. This is the game clincher , all devices tell you to get the device blue light flashing fast , do not do this , get it to flash about once every 3 seconds , go through smart life app settings and when asked click on the slow flashing icon. It will then ask you to connect to Internet ( I thought but I am connected ) but it wants you to reconnet and select WiFi that starts with smartlife (emitting from the device) when it says connected but without Internet, click back to the smart life app and voila it is connecting . I have done all my devices like this and all work fine .
Once all done you can turn the hub 5Ghz back on.
Great hub , just needed someone from bt to look in to this .