Just fount this on
https://wowwiki.fandom.com/wiki/UIOBJECT_GameTooltip
"When you mouse over things in the game world, the game engine internally calls the equivalent of :Set____() - not the actual Lua method. In particular, this means that hooked GameTooltip methods will never trigger for engine-generated tooltips. Hooks will however catch all other tooltips generated from the UI itself. For non-item/unit tooltips you will even see :AddLine and :AddDoubleLine calls."
Does this mean that I need to hook the AddLine and AddDoubleLine scripts instead?