Scene not syncing

I have created a game similar to a board game where multiple players will be able to see a main playing area and will be dealt tiles / cards.

I have a Lobby, where a host may create a room. The host is automatically added to the room as a random player name. A player may find and join that room also with a random player name. All is good so far.

When the host clicks the "Create Game" button both the player that is connected and the host are navigated to the game. It does seem that we are in the same room, but it seems as if we are playing completely separate games. All of the cards and tiles dealt should be synced across all players connected to the game. Although the players are all in the same room, it appears they are all playing their own version of the game.

I am just learning C# and game development, so you will need to explain things in non-technical terms.