For a smooth experience, it's very important that you are connected to a reliable network and that your device's signal is strong. A stable Wi-Fi connection or mobile data coverage alone is not always enough to guarantee a solid connection, because local networks can slow down and get overburdened at times. This is especially true if you play in a moving vehicle or on underground public transport.
As with any other online service, we recommend playing over Wi-Fi with a good internet service provider, or at least a solid 4G/5G connection with a reliable carrier.