First, try the following:

1. Ensure that both the Popsical and your Phone are connected to the same WiFi network.
2. Restart your Popsical, ensure it is connected to WiFi, and NOT to Ethernet (see point 3).
3. From the “main menu”, go to “settings”, select “network settings”, select your wifi-network, press “forget”, then re-enter your wifi password and click “connect”. Press the “back” button to return to the “main menu”.
4. Force-quit the Phone App, re-input a new party code.
5. Reconnect your Phone to the same WiFi-network as your Popsical device.
6. Ensure that port 8080 is not restricted on your network, or connect to a different network.
7. Ensure both Popsical and Phone are on the same subnet.