SOLVED!
FIX
The data was being reverted due to the fact that when I changed the data, it was detected with the Heartbeat function and reverted back right before the server truly closed.
TIP
When trying to test :BindToClose() in the main game, try using the Migrate feature to test if it works. When migrating, the game will freeze for a second when it's already closed, therefore showing what is happening while the server is closing.
** You are now Level 3! **