Slide master/ Focus order

Hello! I am updating a storyline project created by a colleague who has left the organisation. Slide master has been used to create the project. I am working through the focus order of the slides and there are loads of elements in the focus order box I can't see on the screen, for example text boxes. See screenshot below. I read a storyline article on slide masters and have worked out how to remove elements from the focus order. However the issue is I can't find most of them when I go into slide master view. I'd ideally like to delete all these elements, just struggling to find them! Any advice/ guidance would be welcomed, Jayne :)