When using Game Mode = "PUSH", ServerSide events are not triggered (ie. "On Custom Rcon Command", "On Player Joined Server", etc) are ignored.
When changing to Game Mode = "CUSTOM", it works fine.
This is expected behavior, the game logic is used for custom to emulate the gamemode not vanilla modes. The player proxy etc would be your best bet for push modding.
When using Game Mode = "PUSH", ServerSide events are not triggered (ie. "On Custom Rcon Command", "On Player Joined Server", etc) are ignored. When changing to Game Mode = "CUSTOM", it works fine.