Steps to reproduce:

1. Download and import attached user project.
2. Open scene: NetMessageTest
3. Press play.
4. Press Setup Server.
5. Press Setup Client
6. Press Send Score.
7. Inspect the console.

Expected result: Debug log that client has got the score.
Actual result: Client did not get the message.

Note, this line does not work:
- NetworkServer.SendToAll(MyMsgType.Score, msg);

But this does work:
- NetworkConnection.Send(MyMsgType.Score, msg);
(see line 32-36 of NetMessagesTest.cs)

Reproduced on: 5.4.0b14, 5.3.4f1