ModuleScripts do not run without being required. Take a look at this article for more information: ModuleScript | Documentation - Roblox Creator Hub
This means that your code isn’t being run when the server starts up, and therefore your initial PlayerAdded event won’t be initialised in time for it to trigger. Generally, when working with ModuleScripts we don’t use the “PlayerAdded” event - personally I handle players being added and removed in server scripts and use ModuleScripts for functions that would do something with the player.
Hope this helps,
-Tom 