[2020] Lost connection to server bug

Hey @Luna_Silverleaf, is your brother playing over the same network as you are and on the same console?

Is your console connected through a wired or wireless connection?

Do you have any issues in any other server?

Are you and your brother using the same internet service provider?

Could you try both hosting and joining a singleplayer cooperative session with him and let us know if similar issues occur?