Does it work on public Wi-Fi like a café or university?

It depends on the network's security configuration.

Many public Wi-Fi networks (cafés, airports, universities) employ "Client Isolation" or "AP Isolation". This prevents devices connected to the same network from seeing or communicating with each other for security reasons.

If client isolation is active, your phone won't be able to connect to the IP address on the QR code. AirBridge works best on your home or private office Wi-Fi.