① Your phone's Wi-Fi may not be connected to your device's hotspot, or it may be connected to a different network. Disconnect your phone from the current network and manually connect to your device's Wi-Fi hotspot. If necessary, restart your device and try again.
② If you change the Wi-Fi name or password in the app, restart your device, ignore the previously connected Wi-Fi hotspot, and search for and connect to the Wi-Fi hotspot that appears after the name change.