If a red Wi-Fi symbol pops up in your game, whether you are in a match or just looking around, it means that there is a loss of quality in your connection. This might cause lag should you decide to start a match.

WiFi connections are not always reliable as they are affected by outside factors (like movement and physical obstacles for instance) and are generally less stable than data connection.

Try connecting to a 3G or 4G network instead, as it should stabilize your connection.