SyncVar synchronization doesn't work when the Server is started in Standalone. But it works when Server is in Editor

How we can reproduce it using the example you attached

--- see attached video in comments ---
1 Open attached project
2 Open scene LobbyScene
3 Build and Run Standalone build
4 In Standalone press "LAN Server Only"-button
5 In Editor press Play and "LAN Client"-button and then press "Start"-button

Actual results:
notice that player's "Gun" is green on the Server, but black on the Client

Expected result:
player's "Gun" should be green on both Server and Client