Clients not connecting. Doing open 127.0.0.1 also results in the client just loading the “Game Default Map”.
Did find this in the log, however:
[2021.04.01-18.40.11:733][758]LogNet: UIpConnection::HandleSocketSendResult: Socket->SendTo failed with error 21 (SE_EADDRNOTAVAIL). [UNetConnection] RemoteAddr: 127.0.0.1:17777, Name: IpConnection_0, Driver: PendingNetDriver IpNetDriver_1, IsServer: NO, PC: NULL, Owner: NULL, UniqueId: INVALID Connection beginning close timeout (Timeout = 0).
I did switch back to Malwarebytes during the period of time when this stopped working, but adding exceptions and closing Malwarebytes completely did not help at all.