[iOS]A communication error causes me to disconnect during a race. /Support Code: 819-0000 is displayed.

You may not be able to play a multiplayer race to its end if your Internet connection or that of players you are racing with is unstable.
Check the following for ways that you may be able to resolve this issue:
・Play in an area where you can get a stable connection.
・Try playing at different times.
・Switch between cellular and Wi-Fi connections.
・Restart your router.
・Check the settings of the following apps or software if you are using them:
- Security software
- Content blocker
- VPN
- Go to Settings, Cellular, Cellular Data Options, then Data Mode, and turn off Low Data Mode. (This option may not be available depending on your OS version.)
・Close apps other than Mario Kart Tour.
・Restart your device and Mario Kart Tour.
・In Mario Kart Tour, go to Settings, scroll down to the System section, and turn on Power Saving.