Extras menu dissapearing

So a while ago I 100%ed the game. Later on I decided to play again in hard mode. But when i created the new save, the extras option disappeared. Saving and loading my old save doesn't change anything. According to a reddit post i read you need to beat the game all over again and unlock everything?
Isn't there any other way?

EDIT: Defeating the final boss in the old save also works.