What is it with students not being able to navigate a textbook?

I’m in week 3 of teaching two online asynchronous classes. A few from each class have hit me with “I can’t find the assignment/questions/readings in the textbook.” I even provide page numbers. At first I thought maybe they had a prior edition. But when I looked at the books they had the right one. Is this some kind of gamesmanship that I’m not picking up on? Or do these folks struggle with comprehension?