When I disable and then re-enable the Topbar, I notice that the player’s name, age restrictions and health bar are no longer visible. The chat, inventory and emotes icons are there, but anything that is usually seen in the right sight of the Topbar no longer appears.
The bug reproduces when the LocalScript is placed in StarterPack, StarterPlayerScripts, or ReplicatedFirst. When it is placed in StarterGui or StarterCharacterScripts, the Topbar appears with the health bar as normal.
The bug does not occur without a relatively large waiting time. Having wait() does not cause any issues, but wait(1) does.
Note that I tested this in a completely fresh place, baseplate and all.
local StarterGui = game:GetService("StarterGui")
StarterGui:SetCore("TopbarEnabled", false)
wait(1)
StarterGui:SetCore("TopbarEnabled", true)