This claims Creates a new character for the player, removing the old one. Also clears the player’s Backpack and PlayerGui.

However, that doesn’t seem to be the case. The character is spawned but the contents of the PlayerGui are not removed. I can do this myself, of course, but either the wiki is wrong, or the method is broken.

Do you at all have ResetPlayerGuiOnSpawn set to false?

Nope, it’s set to true.