I’m following a guide to get all the skulls but like the title says one is missing. I know I have to be in remastered mode but it does not appear. I even changed the difficulty to legendary but nope. I do not have the achievement either.
The skull can be found on easy difficulty, be sure to jump into the right vent at the first stage of the Library(link).
I did I even took a screenshot nothings there
That’s odd. A possible solution could be adding another guest / inviting a friend and try to find the skull on co-op.