If CharacterAutoLoads is set to false, the contents of the StarterGui are not cloned into players' PlayerGui. It looks like the client does not clone it in until LoadCharacter is called on the player and their character is loaded. I'm on Windows 7 with the latest version of studio and the client (it happens on both).
Expected behavior: Contents from the StarterGui should be cloned into the PlayerGui as soon as the loading screen disappears, regardless of whether there's a character or not because not all games rely on characters in the same way the ROBLOX does.
Repro file (right click > save link as):
It's just an empty baseplate with CharacterAutoLoads set to false and a ScreenGui+Frame in the StarterGui.
There's a similar thread about this, but according to him all GUIs are gone when he disables CharacterAutoLoads, so I'm not sure if it's a different bug and I decided to post a separate thread.