Perhaps he finds the stories easier to process quickly and doesn't feel the need to respond immediately, while the texts require more thought and a proper reply that he's not ready to give yet.
It could be that he's passively consuming the stories but has something on his mind that's preventing him from actively engaging with your texts. Maybe he's busy or dealing with personal issues.
Maybe he's just more interested in the visual aspect of your stories for now and hasn't had the time or energy to respond to your texts.