When I am trying to add a new device to my yeelight account, I am unable to add it. During the process, it fails after reaching 100% stating connection timeout.
The app offered me to connect manually to the light. After failure during first addition (even tried resetting), the yeelight SSID cannot be found. As such I need to reset the device everytime I want to add the device.
After reset, i can find the yeelight SSID. Please see screenshot below.
Could you setup a hotspots with another phone and try connecting the bulb to it to see if it works? If yes, you can try change DNS of your router to 8.8.8.8 and then connect again.